18.—(1) Any party may apply to the Tribunal for a summons to require any person to—
(a)attend, at such time and place as is specified in the summons, to give evidence as a witness;
(b)file, within the time specified in the summons, any document in his custody or under his control which the Tribunal considers it necessary to examine; or
(c)both attend and file in accordance with sub-paragraphs (a) and (b) above.
(2) Any summons issued under paragraph (1) above shall—
(a)state the name and address of, or otherwise describe, the person to be served; and
(b)be signed by the Chairman of the Tribunal issuing it,
and it shall be the responsibility of the party who made the application under paragraph (1) to serve the summons.
(3) No person may be required under this rule to file a document to the extent that the Tribunal is satisfied that—
(a)it is a protected item; or
(b)it should not otherwise be disclosed,
and, for the purpose of satisfying itself in respect of any such document, the Tribunal may—
(i)require that the document be produced to the Tribunal;
(ii)conduct any hearing in the absence of any party; and
(iii)invite any party to make representations.
(4) A witness summons shall be sent so as to be received by the person to whom it is addressed not less than seven days before the time specified in the summons.
(5) Every summons under paragraph (1) shall contain a statement warning of the effect of paragraph 11(3) to (6) of Schedule 4 (offences connected to summonses).
(6) No person shall be required, in obedience to a summons under paragraph (1), to travel more than 16 kilometres from his place of residence unless the necessary expenses of his attendance are paid or tendered to him in advance, and when the summons is issued at the request of a party, those expenses shall be paid by that party.
(7) The Tribunal may, upon the application of the person to whom the witness summons is addressed, direct that the witness summons be set aside or varied.