THE FACTS The facts of the case as submitted by the applicant may be summarised as follows: The applicant is an Austrian citizen, born in 1924 and resident in V. or K. near S. From the statements and from documents submitted by him it appears that he was arrested on .. November 1968 and remanded in custody. At the same time preliminary investigations were instituted against him on the suspicion of having misused official powers (Missbrauch der Amtsgewalt). On .. May 1969, the applicant was convicted by the Regional Criminal Court (Landesgericht für Strafsachen) in V. of having committed this offense and sentenced to three years' severe imprisonment with the additional penalty of "sleeping hard" (hartes Lager) and fasting once every three months. From the judgment it appears that the applicant, who was between ... and ... 1968, the personal assistance in charge of public relations (Pressereferent) to the Austrian Minister of the Interior, had made available to the secret organisation of a foreign country certain secret information concerning the 9th World Youth Festivals and had photocopied certain secret documents concerning the events in Czechoslovakia in 1968, with the intention of passing them on to the secret service organisation of that foreign country. The Court found that, by reason of these acts he had misused the official powers vested in him by to the detriment of the Republic of Austria. The applicant lodged with the Supreme Court (Oberster Gerichtshof) in Vienna a plea of nullity (Nichtigkeitsbeschwerde) against his conviction and an appeal (Berufung) against his sentence. In his plea of nullity he apparently alleged that various provisions of Article 281 of the Code of Criminal Procedure (Strafprozessordnung) had been violated by reason of the fact that the public had been excluded during certain parts of the trial, that certain expert opinions had not been obtained and that the Regional Criminal Court had wrongly assessed the evidence before it. He apparently also alleged that procedural law had been violated in that his conviction was based on certain information given by a former Czech diplomat, Dr. B., and a member of the German secret service which information had been introduced in the proceedings by means of hearsay evidence. In fact, the Court had heard as witnesses two officials of the Austrian Security Service, Drs. H. and P., who had given evidence as to certain information received from Dr. B. and an unidentified official who was employed with a secret service organisation in Munich. H. and P. had received permission from their superiors to give evidence as to certain facts, but no permission had been given to reveal the identity of the foreign official, and this had been assured by the Austrian authorities. Before the trial the applicant has requested to summon an informed representative of the Federal Information Service (Bundesnachrichtendienst) at Munich-Pullach and such summons had been issued by the Court. However, the Court established during the third day of the trial, namely on .. May 1969, that the witness so summoned had failed to appear. The applicant alleged in this respect that such witness should have been heard by rogatory commission in Munich and that it had been unlawful to obtain the hearsay evidence of Drs. H. and P. On .. February 1970, the Supreme Court partly allowed the plea of nullity and the appeal. It confirmed the applicant's conviction having misused his official powers by passing on secret information concerning the 9th World Youth Festivals, and of having attempted this offence by photocopying certain documents, but acquitted him of the charges of having attempted to misuse the official powers by photocopying certain other documents. At the same time the Supreme Court reduced the sentence to two years' and nine months' severe imprisonment with the additional penalty of fasting once every three months. The Supreme Court rejected the applicant's allegations that procedural law had been violated by reason of the fact that the public had been excluded during part of the trial and that certain expert witnesses had not been examined by the Regional Court. It also considered that the failure to obtain the evidence of a German secret service man by means of a rogatory commission did not constitute any violation of the law since the applicant had not made any application in this regard during the trial and, in any event, any such request to a German Court would have had no prospects of success in view of the relevant provisions of the German Code of Criminal Procedure and international custom in this respect. The Supreme Court then dealt with the question of the alleged hearsay evidence given by Drs. H. and P. during the trial. It found that it was, in principle, not permissible, both under the relevant provisions of the Austrian Code of Criminal Procedure and under Article 6 (3) (d) of the Convention on Human Rights to obtain hearsay evidence where it is possible to obtain direct evidence on the subject matter concerned. Interpreting Article 6 3 (d) of the Convention, the Supreme Court said: "Under Article 6 3 (d) of the Convention, the accused person has the right - already emerging from Article 249 of the Code of Criminal Procedure - 'to examine or have examined witnesses against him'. However, 'witnesses against him' within the meaning of the Convention are only such persons who have directly observed the burdening facts, as otherwise the right to examine them would have no meaning. Neither the accused nor his counsel would be in a position to ask significant questions or make relevant allegations with regard to the evidence given by an official whose licence to testify in court has been restricted to the effect that he may not disclose the source of his information. The right to examine witnesses about evidence submitted by such organs whose identity must be concealed by means of an official restriction on the authorization to testify is therefore as such excluded from the prohibition expressly contained in Article 6 3 (d) of the Convention,, namely to stop witnesses from being questioned by the defendant." The Supreme Court continued to say that, only where a witness was otherwise unattainable was it possible to introduce in the proceedings the evidence to be given by that person by examining a third person. However, a witness whose identity may not be disclosed was not for that reason an unattainable witness. Thus it was not possible to examine witnesses who are allowed only to give fragmentary evidence as to facts reported to them by third persons but must conceal the source of their information. However, the Supreme Court found that those general considerations were not directly applicable in the present case. The unidentified informer was not a secret service agent but a high official employed with the Federal Information Service in Munich, being an organisation whose identity was sufficiently clear. Moreover, an informed representative of that service had been summoned to appear at the trial but had failed to come. Having regard to this situation it was clear that, even if the name of the official concerned had been revealed, he would have similarly failed to appear at the trial and the Austrian authorities had no power to ensure the appearance of a foreign government official. Consequently, the witness was not unavailable by reason of the refusal of permission to give evidence, but he was, in fact, unattainable which justified the hearing of hearsay evidence. Apart from this it was for the Court to assess the facts and appreciate the evidence before it and the court's findings in this respect were not subject to review on appeal. On the other hand, where the Court wrongly assessed the law in regard to the facts established, the judgment must be set aside. This was required in respect of certain documents which, according to the facts established, were no longer secret at the time when they were photocopied. Consequently, the conviction had been quashed in these regards. Complaints The applicant now complained that his right to examine or have examined witnesses against him and to obtain the attendance and examination of witnesses on his behalf under the same conditions as witnesses against him, had been violated in his case. He explained that before the trial started he had made and application to the Regional Criminal Court to summon an informed representative of the Munich Federal Information Service. However, the fact that Drs. H. and P. had not been granted permission to disclose in court the identity of the person from whom they had received their information, prevented him from examining these witnesses in this respect and also from obtaining the attendance and examination of the person concerned. Moreover, the Court had failed to obtain the evidence of that person by means of a rogatory commission. The applicant further explained that his conviction was based primarily on information given by Dr. B. and a member of the German secret service. However, these persons had not been examined by the Court. Instead the evidence of Drs. H. and P. was obtained who reported that Dr. B. and the German secret service agent had told them, namely that the applicant had worked for the Czech secret service and had passed information to the German secret service. According to the applicant, these allegations were not true and he had wished to put precise questions to the persons concerned thus proving his innocence. He alleged violations of Article 6 3 (d) of the Convention. Proceedings before the Commission The application was lodged with the Commission on 16 February 1970 and was registered on 20 March 1970. However, on 2 April 1971 the Commission decided to strike the application off the list on the ground that the applicant had shown no interest in its maintenance. In fact, there had been no communication from the applicant during a certain period and efforts on the part of the Commission's Secretary to get in touch with him had failed. By letter of 25 April 1971 the applicant enquired about his application and, after the text of the Commission's decision of 2 April 1971 had been communicated to him the requested at once that his application should be restored to the list of cases before the Commission. He confirmed that he had, in fact, not lost interest in having his case examined and gave explanations as to the reasons for his failure to keep the Commission informed about his whereabouts. He stated that he had been released from prison on 16 October 1970 but that he had left forwarding addresses with the prison authorities and had also notified the judicial authorities and the police of his whereabouts. It was true that he had failed at once to inform the Commission of his change of address, for which he offered his apologies, but he had assumed that the prison authorities would forward any correspondence addressed to him in prison or that the postal authorities would have delivered the Secretary's letters addressed to him at his new address at K. near S. In any event, it would have been easy for the Ministry of Justice to ascertain his correct address. On 23 July 1971 the Commission, in accordance with its usual practice in such cases, considered these explanations with a view to deciding whether the circumstances of the case as a whole justified its restoration to the list of cases. In this connection it had special regard to the relatively short period during which contact with the applicant had been interrupted and found that a misunderstanding could not be excluded. Consequently, the circumstances of this case did so justify its restoration to the list of cases. The Commission examined the applicant's complaint on 17 December 1971 and decided, in accordance with Rule 45, 3 (b) of the Commission's Rules of Procedure, that notice thereof should be given to the Austrian Government and that the parties should be invited to submit observations in writing on the admissibility of the application. The respondent Government submitted their observations on 18 March 1972. The applicant replied on 2 April 1972. Submissions of the parties 1.   The respondent Government first referred to the procedure of the Commission to restore to its list cases which have previously been struck out. They considered that such procedure was not envisaged under the Convention and appeared to circumvent the provisions of Article 26 of the Convention. The Government then made submissions regarding the substance of the applicant's complaint. They explained that the judgment of the Vienna Regional Criminal Court, by which the applicant had been convicted and sentenced, had been based on the evidence of numerous witnesses, of experts, as well as on documentary evidence, including official files and the applicant's passport. The applicant now complained under Article 6 3 (d) of the Convention, that certain witnesses, who were members of a German secret service organisation and whose evidence had been introduced at the trial by means of hearsay evidence, had not been examined either at the trial itself or by means of rogatory commissions in the Federal Republic of Germany. However, under Article 2 of the Treaty of 22 September 1958 between the Republic of Austria and the Federal Republic of Germany regarding mutual assistance in legal matters, such assistance was not granted where the proceedings concerned relate to political matters or are connected therewith. It was true that the Court had, in fact, summoned witnesses in the Federal Republic of Germany to appear and give evidence at the trial but these summonses had only been transmitted by the German authorities to the witnesses concerned because the authorities did not know that the proceedings concerned related to a political matter. Otherwise, they would certainly have refused to communicate the summonses and this would have been in accordance with both the above Treaty and with the general rules of international law as stated in Article 2 of the European Convention on Mutual Assistance in Criminal Matters. Austria herself had made a reservation, inter alia, in respect of political cases and it could therefore not expect any different treatment from other countries. It was thus clear that the law did not permit the summoning of witnesses or their examination by rogatory commission and where the Vienna Regional Court had nevertheless issued such summonses it had obviously attempted to safeguard, as much as possible, the procedural rights of the accused. Apart from this, the applicant had failed during the trial itself to make applications for the examination of witnesses abroad and had therefore not exhausted the domestic remedies in this respect. As regards the examination by the Court of Drs. H. and P. it was not true that they had simply given hearsay evidence. Insofar as these witnesses had reported their contacts with foreign informers they had clearly given direct evidence. But, insofar as they had reported what these foreign informers had told them, the Court had fully appreciated this element in their testimony and the Government quoted a passage in the judgment of the V. Regional Criminal Court in support of this allegation. The Government submitted that it had been necessary to hear the evidence of Drs. H. and P. because it had not been possible, in fact and in law, to obtain the direct evidence in Court. In this respect the Government referred to the reasoning of the Supreme Court in the present case and also a similar decision by the Federal Court of the Federal Republic of Germany, dated 1 August 1962. Furthermore, in accordance with the principle of discovering the actual truth (Prinzip der materiellen Wahrheit), the Court was bound to examine with care the allegations made on behalf of an accused person in the same way as those made against him. But it was not obliged to summon all the witnesses nominated by an accused person, and particularly not those witnesses whose evidence it considered to be irrelevant. In this connection the Government referred to a decision of the Netherlands Supreme Court regarding Article 6 of the Convention and to the Commission's Report of 11 July 1960 on the case of Austria against Italy. In the Government's submission, the applicant in the present case would, in any event, not have gained anything by the disclosure of the name and the official position of the foreign informer, or by his being summoned as a witness, as he would not have appeared at the trial, and his examination by means of a rogatory commission in the Federal Republic of Germany was inadmissible under the law. The Government next referred to the principle of the free appreciation of evidence (Grundsatz der freien Beweisführung) and submitted that hearsay evidence was not as such excluded under Article 6 3 (d) of the Convention as long as the Court took into consideration the particular nature of such evidence. It was clear from the judgment in the present case that the V. Regional Criminal Court had been clearly cognisant of the manifold objections against hearsay evidence. Moreover, it should be stressed that the applicant's conviction had by no means been based only on such evidence but had been supported by a multitude of other evidence. In the Government's submission, the applicant was in fact challenging in his application to the Commission the findings of fact made by the Regional Criminal Court. However, the Commission had constantly held that it had no competence to examine allegations that errors of law or fact had been committed by the domestic courts and, in this connection, had always confirmed that it was not a "court of fourth instance". The Government submitted that, for these reasons, the application should be declared inadmissible in accordance with Article 27 (2) and (3) of the Convention. 2.   The applicant, in his written reply of 2 April 1972, first made submissions explaining that he had never lost interest in his application to the Commission. In fact it had been the Government's fault that the Commission had been unable to contact him after his release from prison in October 1970 and had struck his case off its list. The applicant then dealt with the Government's submission that the judgment of the Vienna Regional Court had been based on the evidence of numerous witnesses, of experts, and on an examination of his passport and contended that this submission was wrong. In fact, as regards experts, his counsel had requested the Court to hear expert witnesses with regard to questions of the methods and practices employed by intelligence services as well as questions of constitutional law. However, the Court had refused these applications on the ground that the evidence offered by these experts was neither relevant or admissible. Furthermore, concerning the examination of his passport, the applicant submitted that this evidence was not designed to prove charges relating to espionage. Finally, as regards certain witnesses whose evidence had been used against him, the applicant contended that their testimony had either been contradictory in itself or had been insufficient to prove the charges against him. In this connection the applicant referred to the evidence of three witnesses in particular and quoted their statements at the trial or during the preliminary investigations. In the applicant's submission, the two officials Drs. P. and H., on the other hand, played a decisive part in the criminal proceedings against him. He contended that they were regarded by the trial court as being both experts in secret service matters and witnesses to the facts and that it was inadmissible under the Code of Criminal Procedure to give evidence in this double capacity. Apart from this, Dr. P. had himself been the subject of judicial investigations in his then capacity as Head of the State Police. Moreover, the Court had contained itself in obtaining hearsay evidence instead of using all possibilities which were at its disposal to arrive at the whole truth. It was perhaps true that in the strict sense of the law it would not have been possible to obtain evidence abroad by means of rogatory commissions, but in practice this was nevertheless successfully accomplished. In fact, in a case relating to espionage in the Federal Republic of Germany (The Porst Case) the German courts had obtained in the United States of America the evidence of a witness who had testified against the accused. A further contradiction emerged clearly from the Government's own submissions when they explained, on the one hand that, contrary to the provisions of the law, witnesses in the Federal Republic of Germany had in fact been summoned by the Regional Court and alleged, on the other hand, that the applicant had failed to make applications during the trial for the summons of witnesses abroad and had therefore not exhausted the domestic remedies. In the applicant's submission, it was either possible or it was not possible in political cases to obtain evidence from abroad. If it was possible, the prosecution authority should have obtained such evidence even before the trial, but if it was not possible the Court should not have transmitted such summonses as requested by him. To do favours to an accused person as suggested by the Government was neither envisaged by the law nor was it normal procedural practice. Moreover, through the evidence given by Drs. P. and H., the Court had obtained the remote evidence of third persons (informers) who had informed the undisclosed sources of information of Drs. H. and P. and who equally remained anonymous. It was in the applicant's submission, clear that the Court had made no attempt at obtaining the evidence of the immediate witnesses against him and it was not true that his conviction was based on a multitude of other evidence, as the Government had contended. He therefore maintained that Article 6 (3) (d) of the Convention had been disregarded and he requested the Commission to admit his application. THE LAW The applicant has complained of his conviction and sentence by the Regional Criminal Court of Vienna and of the court proceedings concerned. However, in regard to the judicial decisions of which the applicant complains, the Commission has frequently stated that, in accordance with Article 19 (Art. 19) of the Convention, its only task is to ensure the observance of the obligations undertaken by the Parties in the Convention. In particular, the Commission is not competent to deal with an application alleging that errors of law or fact have been committed by domestic courts, except where it considers that such errors might have involved a possible violation of any of the rights and freedoms set forth in the Convention. In this respect, the Commission refers to its established case-law (see e.g. decisions on the admissibility of applications No. 458/59, Yearbook, Vol. 3, pp.222, 232 and No. 1140/61, Collection of Decisions, Vol. 8, pp. 57, 62). In the present case the applicant has complained that Article 6 (3) (d) (Art. 6-3-d) of the Convention has been violated by reason of the fact that the Regional Criminal Court in V. failed to obtain the attendance in court of the persons who could have given direct evidence in his case. Instead, the Court obtained the hearsay evidence of two high officials of the Austrian security services whose authorization to testify in court had been limited to the extent that they were not allowed to disclose the names of the persons who had given them information and he had thus been prevented from examining these witnesses in this respect or from obtaining the attendance in court and the examination of the direct witnesses concerned. Moreover, his conviction had been based primarily on hearsay evidence. Article 6 (3) (d) (Art. 6-3-d) of the Convention provides that everyone charged with a criminal offense has the right "to examine or have examined witnesses against him and to obtain the attendance and examination of witnesses on his behalf under the same conditions as witnesses against him". Interpreting this provision, the Commission has consistently held that Article 6 (3) (d) (Art. 6-3-d) of the Convention is aimed at ensuring in criminal proceedings equality between the defence and the public prosecutor's office as regards the calling and interrogation of witnesses, but does not give an accused person an unlimited right to obtain the attendance of witnesses in court. The domestic law of the High Contracting Parties could thus lay down conditions for the admission and examination of witnesses provided that such conditions were identical for witnesses on both sides. Similarly, the competent court was free, subject to respect for the terms of the Convention and particularly for the principle of equality established by Article 6 (3) (d) (Art. 6-3-d) of the Convention to refuse calling witnesses nominated by the defence for instance on the ground that the court considered their evidence as being unlikely to assist in ascertaining the truth (see, for example, opinion of the Commission in its report of 31 March 1963 on application No. 788/60, Austria against Italy, paras. 112, 115). The Commission finds that the same considerations are applicable in respect of an applicant's right under Article 6 (3) (d) (Art. 6-3-d) of the Convention to examine or have examined witnesses against him as both part of this provisions are closely interrelated. Thus, as accused person does not have an unrestricted right under this provision to put questions to witnesses testifying against him in court, but the exercise of this right must be governed by the Court's appreciation whether or not such questions are likely to assist in, and thus necessary for, ascertaining the truth. Two questions arise under Article 6 (3) (d) (Art. 6-3-d) of the Convention as to the conduct by the Regional Court of the proceedings in the present case:  first, whether or not the applicant's right to "obtain the attendance and examination of witnesses on his behalf under the same conditions as witnesses against him" has been violated by reason of the fact that the informer himself has not appeared to give evidence at the trial. In this respect the Commission observes that the Regional Criminal Court in Vienna acting in accordance with the applicant's request, had, in fact, tried to obtain the attendance in court of any informed member of the German Secret Service Organisation which had transmitted information about the applicant to the Austrian authorities. However, this attempt had failed as the witness summoned had not appeared and, given the reservations as to political offenses in the Austro-German Agreement relating to Mutual Assistance in Criminal Matters as well as to the European Convention on Mutual Assistance in Criminal Matters, it could not have been possible for the Austrian courts to compel such witness to appear or to obtain his evidence by means of rogatory commissions in the Federal Republic of Germany. In these circumstances the Commission finds that, apart from the fact that the applicant has not made any submissions as to the nature of the evidence of the witness whom he wished to call and whose attendance the court failed to obtain, there were factual obstacles resulting from the character of the charges against the applicant which prevented such attendance rather than any deliberate act or omission on the part of the Court for which the Austrian Government would be responsible under the Convention. The second question  that arises in this context is whether or not the applicant's right "to examine or have examined witnesses against him" has been violated by reason of the fact that the two members of the Austrian security services who gave evidence against him, namely Drs. H. and P. were not allowed, under an official limitation of their authorization to testify, to disclose the names of the persons who had supplied them with information about the applicant. In this respect the Commission observes that it emerges clearly both from the judgment of the Supreme Court of 11 February 1970 and from the applicant's submissions to the Commission that, in spite of the above limitation on their testimony, the applicant knew that the source of the information of Drs. H. and P. was a high official of the Federal Information Service in Munich, being an organisation whose identity was sufficiently clear to him. He further knew that Dr. B., a former Czech diplomat, had given information about him to the Federal Information Service which had passed such information on to Dr. H. in Vienna. The only element, therefore, which by reason of the official limitation to testify, remained undisclosed and thus unknown to the applicant was the name of the German official at the Federal Information Service with whom Dr. H. had been in contact. The Commission finds, however, that the applicant has not shown that the revealing of the name of that official was, in the circumstances, necessary as such for the Court's ascertainment of the truth of the criminal charges against him. Indeed, the applicant himself does not allege that he suffered any prejudice in this respect other than that he was thus prevented from summoning this German official and from obtaining his evidence in court. However, with regard to this allegation, the Commission has already established that it was impossible as a matter of fact to obtain the attendance in court of any member of the German Secret Service Organisation concerned or otherwise to obtain evidence directly from this organisation. It follows that in the circumstances, there was no appearance of a breach of the applicant's rights guaranteed under either of the provisions of Article 6 (3) (d) (Art. 6-3-d) of the Convention. On the other hand, there is another aspect of this situation in that the question should be considered whether, as a result of the applicant's right to a fair hearing within the meaning of Article 6 (1) (Art. 6-1) of the Convention has been violated by reason of the fact that the Regional Criminal Court in Vienna obtained, and based its judgment on, evidence which may be described as "hearsay" evidence and which the applicant was, by the virtue of such evidence, unable to challenge with regard to its substance. The Commission has examined this question ex officio and it finds that an issue under the general provisions of Article 6 (1) (Art. 6-1) of the Convention may arise even where it has previously established that there is no appearance of a breach of any of the specific "minimum" rights mentioned in para. (3) of Article 6 (Art. 6-3) including, as in the present case, Article 6 (3) (d) (Art. 6-3-d). In this respect the Commission refers to its opinion in the report of 15 March 1961 on application No. 343/57, Nielsen against Denmark, para. 52. The Commission first points out that it is a principle of law in many countries, including Austria, that the court is free to assess the value of whatever evidence is put before it and the Commission, as has already been stated, has no competence to deal with allegations that errors of law or fact have been committed by domestic courts except where it considers that such errors might have involved a possible violation of the rights and freedoms set forth in the Convention. The right to which reference could be made in the present case, is the general right set forth in Article 6 (1) (Art. 6-1) of the Convention, that in "the determination .... of any criminal charge against him, everyone is entitled to a fair and public hearing within a reasonable time by an independent and impartial tribunal established by law". However, under this provision the Commission is again not called upon to decide whether or not the domestic courts have correctly assessed the evidence before them, but only "whether evidence for and against the accused has been presented in such a manner, and the proceedings in general have been conducted in such a way, that he has had a fair trial" (see the Commission's conclusion in its report on the Nielsen Case, supra, para. 52). In the present case the Commission observes that the applicant's conviction by the Regional Criminal Court in Vienna has by no means been based solely on the hearsay evidence given by Drs. H. and P., but that there was other evidence weighing against him. Indeed, the judgment of 23 July 1969 of the V. Regional Criminal Court shows that the evidence on which the Court relied was of a variety of sources and quality, including several witnesses whose evidence could not be qualified as "hearsay" evidence, as well as documentary evidence and a factual element which could be interpreted as amounting to a confession. Apart from this, it further emerges clearly from the above judgment that the Regional Criminal Court in V. has been fully aware of the nature of "hearsay" evidence and of the objections that might be raised against it. It has therefore given a particularly careful and critical attention to the examination and evaluation of this evidence. Finally, there is nothing in the applicant's submissions to suggest that he has been prevented in any way from challenging the veracity of the statements made by Drs. H. and P. or from adducing evidence on his behalf, or otherwise from putting his defence before the Court. The Commission finds therefore that in the present case there has equally been no appearance of a breach of the applicant's right to a fair hearing within the meaning of Article 6 (1) (Art. 6-1) of the Convention. An examination by the Commission of the applicant's complaints as they have been submitted, including an examination made ex officio, does therefore not disclose any appearance of a violation of the rights and freedoms set forth in the Convention and in particular in Article 6 (Art. 6). It follows that the application is manifestly ill-founded and must be rejected in accordance with Article 27 (2) (Art. 27-2), of the Convention . For these reasons, the Commission DECLARES THIS APPLICATION INADMISSIBLE