s 54 Determining competence of witnesses.
(1) Any question whether a witness in criminal proceedings is competent to give evidence in the proceedings, whether raised— (a) by a party to the proceedings, or (b) by the court of its own motion, shall be determined by the court in accordance with this section. (2) It is for the party calling the witness to satisfy the court that, on a balance of probabilities, the witness is competent to give evidence in the proceedings. (3) In determining the question mentioned in subsection (1) the court shall treat the witness as having the benefit of any directions under section 19 which the court has given, or proposes to give, in relation to the witness. (4) Any proceedings held for the determination of the question shall take place in the absence of the jury (if there is one). (5) Expert evidence may be received on the question. (6) Any questioning of the witness (where the court considers that necessary) shall be conducted by the court in the presence of the parties.