29.—(1) Evidence before the tribunal may be given orally or, if the tribunal so orders, by sworn or written statement, but the tribunal may at any stage of the proceedings require the personal attendance of any deponent or maker of a written statement.
(2) The tribunal may receive evidence of any fact which appears to the tribunal to be relevant, whether or not the evidence–
(a)would be admissible in a court of law, or
(b)was available to the Secretary of State when the disputed action was taken.
(3) The tribunal may require any witness to give evidence on oath or affirmation which may be administered for the purpose by the chairman.