reg 87 Presence of witnesses
(1) Except for a defendant and any expert or character witness, a witness as to fact shall not, except by leave of the court, be in court while not under examination. (2) If while a witness is under examination a question arises as to the admissibility of a question or otherwise with regard to the evidence, the court may direct the witness to withdraw until the question is determined. (3) The court may direct any expert or character witness present in court to withdraw if it considers his presence undesirable. (4) For the purposes of this rule a witness is in court if he is able to see and hear the court through a live link (and for this purpose any impairment of eyesight or hearing is to be disregarded).