s 29
(1) For the purposes of this Part of this Act, the Court of Criminal Appeal may, if they think it necessary or expedient in the interests of justice— (a) order the production of any document, exhibit, or other thing connected with the proceedings, the production of which appears to them necessary for the determination of the case ; (b) order any witness who would have been a compellable witness at the trial to attend and be examined before the Court, whether or not he was called at the trial ; and (c) subject to subsection (3) below, receive the evidence, if tendered, of any witness. (2) Without prejudice to subsection (1) above, where evidence is tendered to the Court under that subsection the Court shall, unless they are satisfied that the evidence if received would not afford any ground for allowing the appeal, exercise their power of receiving it ifi— (a) it appears to them that the evidence is likely to be credible and would have been admissible at the trial on an issue which is the subject of the appeal ; and (b) they are satisfied that it was not adduced at the trial but there is a reasonable explanation for the failure to adduce it. (3) Subsection (1)(c) above applies to any witness (including the appellant) who is competent but not compellable, and applies also to the appellant’s husband or wife where the appellant makes an application for that purpose and the evidence of the husband or wife could not have been given at the trial except on such an application.