THE FACTS The facts of the case, as submitted by the applicant, may be summarised as follows: The applicant is a citizen of the United Kingdom. He was born in 1934 in India and is at present serving a 7-year sentence in W. Prison. On .. July 1970 the applicant was charged by the police with having conspired with 7 other named men and with other persons unknown to evade the control of immigration of Commonwealth citizens into the United Kingdom. More specifically, the applicant was accused of being the  chief organiser of a conspiracy to bring illegally into the United Kingdom 40 Indian immigrants. These Indians had left Delhi on .. April 1970 and were discovered by the Police in a cellar in B. on .. July 1970. The trial of the applicant and the 7 other co-accused started at Leeds Assize on .. November 1970. On .. November 1970 the applicant was convicted of the charge as laid against him and sentenced to 7 years' imprisonment. The applicant applied for leave to appeal against conviction and sentence and this was eventually granted to him on .. November 1971. In his grounds of appeal the applicant made several complaints about the trial proceedings, and in particular the following. He complained: i.   that the police had planted in his diary the telephone number of a co-accused and that, although it was proved at the trial that the handwriting of the number was not the applicant's, the police were not called upon to produce evidence to show in whose handwriting it was. The applicant submitted that the judge should not have allowed the prosecution to adduce this evidence; ii.  that the Crown withheld statements made by prosecution witnesses which they had been in possession of for several months and did not serve them until a few days before the trial, but that nevertheless the evidence of these witnesses was admitted by the court; iii. that, after the defence case was closed, the judge allowed the prosecution to call a witness to rebut evidence given by a prosecution witness in cross-examination. The applicant argued that the testimony of this witness should not have been admitted since all the evidence for both Crown and defence had already been completed. In its judgment of .. March 1972 the Court of Appeal summarised the facts which gave rise to the charge against the applicant, as they had emerged during the course of the trial before the Leeds Assize. The Court went on to state that the evidence against the applicant had consisted of general evidence as to the existence and nature of the conspiracy and in particular of 3 incidents. First, there had been the evidence as to a visit paid by the applicant and his uncle to Bremen in Germany in April 1970. Secondly, there had been the evidence of the applicant and a co-accused trying to recruit a boatman in A. in May of 1970 and, thirdly, there had been the evidence as to a meeting on .. June when final arrangements for the importation of the immigrants had been made. The Court stated that by far the most important of those three matters was the first, namely the visit to Bremen. The Court of Appeal then dealt at length with the applicant's complaint that the trial court had allowed the Crown to call a witness after both the Crown case and the defence had been closed. The Court described the exceptional circumstances in which this had occurred and, in particular, that it would have been quite impossible for the witness to be called any earlier. The Court stated further that after trial judge had considered the matter, which had been expanded very fully in the lower court, he had come to the conclusion that in the circumstances of the case he had a discretion to give leave to the Crown to call the evidence they required. The Court of Appeal considered that the exercise of such a discretion in favour of the Crown must be the rare exception rather than the common rule, but that, for the reasons which it had given, in the present case the trial judge had exercised his discretion in a manner which was beyond criticism. In dismissing the applicant's appeal against conviction, the Court expressed  its view that the trial was in every way beyond criticism and that the applicant had been convicted of the charge against him on an abundance of evidence. Finally, the Court considered and rejected the applicant's appeal against sentence. Complaints The applicant alleges that he did not have a fair trial and in this respect repeats to the Commission the above complaints i. - iii. which he made to the Court of Appeal. The applicant also complains that the sentence of 7 years' imprisonment imposed on him was unlawful. He alleges that the substantive offence of which he was convicted was an offence under the Commonwealth Immigrants Acts 1962 to 1968 for which a fine not exceeding £100 or imprisonment not exceeding 6 months, or both, is provided. The applicant states that it was only after the Immigration Act 1971 had been passed that a penalty of imprisonment of up to 7 years for assisting illegal entry of immigrants could be imposed, and this Act came into force several months after the date when the facts relied upon in the indictment against him took place. The applicant alleges the violation of Article 6 (1), Article 6 (3) (d) and Article 7 (1) of the Convention. THE LAW 1.   The applicant has complained of a violation of Article 6 (1) and (3) (d) (Art. 6-1, 6-3-d) of the Convention in that he did not have a fair trial before the Leeds Assize. He alleges in particular that the police planted the telephone number of a co-accused in his diary; that the Crown withheld statements made by prosecution witnesses until a few days before the trial but that the evidence of these witnesses was nevertheless admitted by the court; also that the judge presiding over the trial allowed a prosecution witness to be called after the evidence for both Crown and defence had been completed. The Commission first finds that none of these complaints relates to the provisions of Article 6 (3) (d) (Art. 6-3-d) of the Convention which secures to everyone charged with a criminal offence 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. The Commission has then considered these allegations in the light of Article 6 (1) (Art. 6-1) of the Convention which provides that, in the determination of any criminal charge against him, "everyone is entitled to a fair and public hearing ... by an independent and impartial tribunal". With regard to the allegation that the police planted a telephone number in the applicant's diary, the Commission notes that, from the documents submitted by the applicant and in particular from the judgement of the Court of Appeal, it is apparent that during the trial there had been a substantial amount of evidence against the applicant, both of a general character and of specific incidents. It appears that the telephone number was only one element in this evidence and the Commission is satisfied that, even if the number was planted, as alleged, this could not have influenced the case against the applicant to such an extent that it prejudiced his right to a fair hearing within the meaning of Article 6 (1) (Art. 6-1). With regard to the complaint that the court admitted the evidence of certain witnesses, whose statements had only been served a few days before the trial, the Commission again does not find any indication that the admission of this evidence made the proceedings inequitable or in any way prejudiced the applicant's right to a fair hearing. With regard to the complaint that the trial judge allowed the prosecution to call a witness after the case for both Crown and defence was closed, the Commission finds first that it is generally within the discretion of the competent domestic court to admit a witness if the court considers that the evidence he will give would be relevant to the matters in issue. The Commission notes that in the present case the witness was allowed to give evidence at a stage in the proceedings when normally no further witnesses could be called. The Commission  notes also that, as stated by the Court of Appeal, the admission of evidence at this late stage of the proceedings must be regarded as a rare exception. The Commission further finds that there were exceptional circumstances which occurred during the trial and which were described by the Court of Appeal in its judgment and that the applicant has not shown that in these circumstances the trial judge should not have exercised his discretion in favour of the Crown. The Commission is therefore satisfied that in this respect also the applicant was not denied the right to a fair hearing. It follows that this part of the application is manifestly ill-founded within the meaning of Article 27, paragraph (2) (Art. 27-2), of the Convention. 2.   The Commission has examined in the light of Article 7 (Art. 7) of the Convention the applicant's complaint that he was wrongly convicted and sentenced for conspiracy, whereas the offense which he had committed, if any, was one which fell under the Commonwealth Immigrants Acts 1962-1968. Article 7 (1) (Art. 7-1) of the Convention provides that "No one shall be held guilty of any criminal offence on account of any act or omission which did not constitute an criminal offense under national or international law at the time when it was committed. Nor shall a heavier penalty be imposed than the one that was applicable at the time the criminal offence was committed". In this respect the Commission recalls its case-law according to Article 7 (1) (Art. 7-1) "does not merely prohibit - except as provided in paragraph (2) (Art. 7-2)- retroactive application of the criminal law to the detriment of the accused; it also confirms, in a more general way, the principle of the statutory nature of offenses and punishment ('nullum crimen, nulla poena sine lege'); and prohibits, in particular, extension of the application of criminal law  'in malam partem' by analogy. Although it is normally for the Commission to ascertain the proper interpretation of municipal law by national courts, the case is otherwise in matters where the Convention expressly refers to municipal law, as it does in Article 7 (Art. 7). Under Article 7 (Art. 7) the application of the provision of municipal penal law to an act not covered by the provision in question directly results in a conflict with the Convention, so that the Commission can and must take cognisance of allegations of such false interpretation of municipal law."  (Application No. 1862/63, Yearbook, Vol. 8, pp. 190, 198). The Commission's supervisory function, therefore, consists in making sure that, at the moment when the accused person performed the act which led to his being prosecuted, there was in force a legal provision which made that act punishable and that the punishment imposed does not exceed the limits fixed by that provision. In accordance with the decision quoted above, this supervisory function further consists in considering whether the national court, in reaching its decision, has not unreasonably interpreted, and applied to the applicant, the municipal law concerned. In the present case it is not disputed that the offence of "conspiracy" is one that has long existed under common law. Furthermore, the Commission finds that the United Kingdom court, when convicting and sentencing the applicant for conspiracy in no way exceeded a reasonable interpretation of the definition of that crime in holding it applicable to the facts of the applicant's case. An examination by the Commission of this particular complaint in the light of Article 7 (Art. 7) of the Convention does not therefore disclose any violation of that Article. Nor does the Commission find that this complaint raises any issue under any other Article of the Convention. It follows that this part of the application is manifestly ill-founded within the meaning of Article 27, paragraph (2) (Art. 27-2), of the Convention. 3.   The same ground of inadmissibility applies to the applicant's final complaint, that the sentence of 7 years' imprisonment imposed on him was unlawful and could only lawfully have been imposed on him after the Immigration Act 1971 had been passed. This complaint also has been examined by the Commission in the light of Article 7 (Art. 7) of the Convention. The Commission notes that the applicant does not directly allege that the provisions of the Immigration Act 1971 were applied by the court in determining his sentence and that in any event this Act came into force after the date of his conviction (.. November 1970). Furthermore, it is clear that the applicant was not convicted of an offence under the earlier Commonwealth Immigrants Acts but, as he himself admits, of the crime of conspiracy, for which the penalty of 7 years' imprisonment is permissible under English law. An examination by the Commission of this complaint as it has been submitted, including an examination made ex officio, does not therefore disclose any appearance of a violation of the rights and freedoms set forth in the Convention and in particular in the above Article. For these reasons, the Commission DECLARES THIS APPLICATION INADMISSIBLE