Sch 1 para 5
(1) A person cannot be compelled to give any evidence which he could not be compelled to give— (a) in criminal proceedings in the part of the United Kingdom in which the nominated court exercises jurisdiction, or (b) subject to sub-paragraph (2), in criminal proceedings in the country from which the request for the evidence has come. (2) Sub-paragraph (1)(b) does not apply unless the claim of the person questioned to be exempt from giving the evidence is conceded by the court or authority which made the request. (3) Where the person’s claim is not conceded, he may be required to give the evidence to which the claim relates (subject to the other provisions of this paragraph); but the evidence may not be forwarded to the court or authority which requested it if a court in the country in question, on the matter being referred to it, upholds the claim. (4) A person cannot be compelled to give any evidence if his doing so would be prejudicial to the security of the United Kingdom. (5) A certificate signed by or on behalf of the Secretary of State or, where the court is in Scotland, the Lord Advocate to the effect that it would be so prejudicial for that person to do so is conclusive evidence of that fact. (6) A person cannot be compelled to give any evidence in his capacity as an officer or servant of the Crown. (7) Sub-paragraphs (4) and (6) are without prejudice to the generality of sub-paragraph (1).