(1) The court may, if it thinks it necessary or expedient in the interests of
justice--
(a) order the production of any document, exhibit, or other thing
connected with the proceedings, and
(b) order any persons who would have been
compellable witnesses at the trial to attend and be examined before the court,
whether they were or were not called at the trial, or order any such persons
to be examined before any judge of the court or before any officer of the
court or other person appointed by the court for the purpose, and admit any
deposition so taken as evidence, and
(c) receive the evidence, if tendered,
of any witness (including the appellant) who is a competent, but not a
compellable witness, and
(d) where any question arising on the appeal
involves prolonged examination of documents or accounts, or any scientific or
local investigation, which cannot, in the opinion of the court, be
conveniently conducted before the court, the court or any judge thereof may
refer the question for inquiry and report to a commissioner appointed by the
court, and act upon the report of any such commissioner so far as the court
thinks fit, and
(e) appoint any person with special expert knowledge to act
as assessor to the court in any case in which it appears to the court that
such special knowledge is required for the determination of the case,
and
exercise in relation to the proceedings of the court any other powers which
may for the time being be exercised by the Supreme Court on appeals or
applications in civil matters, and issue any warrant or other process
necessary for enforcing the orders or sentences of the court: Provided that in
no case shall any sentence be increased by reason of, or in consideration of
any evidence that was not given at the trial.
(2) The Court of Criminal
Appeal may remit a matter or issue to a court of trial for determination and
may, in doing so, give any directions subject to which the determination is to
be made.
