6(1)Sub-paragraph (2) applies if, on an appeal under Part IV, it is alleged—
(a)that a passport or other travel document, certificate of entitlement, entry clearance or work permit (or any part of it or entry in it) on which a party relies is a forgery, and
(b)that the disclosure to that party of any matters relating to the method of detection would be contrary to the public interest.
(2)The adjudicator or Tribunal must arrange—
(a)for the proceedings to take place in the absence of that party and his representatives while the allegation mentioned in sub-paragraph (1)(b) is inquired into by the adjudicator or Tribunal; and
(b)if it appears to the adjudicator or Tribunal that the allegation is made out, for such further period as appears necessary in order to ensure that those matters can be presented to the adjudicator or Tribunal without any disclosure being directly or indirectly made contrary to the public interest.