27.—(1) In any proceedings under this Act in relation to a person whose return has been requested from a listed territory by the United Kingdom, a designated Commonwealth country, Ireland or a British overseas territory, including proceedings on an application for habeas corpus in respect of a person in custody under this Act—
(a)a document, duly authenticated, which purports to set out evidence given on oath in the United Kingdom, a designated Commonwealth country, Ireland or a British overseas territory (other than the relevant listed territory) shall be admissible as evidence of the matters stated in it;
(b)a document, duly authenticated, which purports to have been received in evidence, or to be a copy of a document so received, in any proceeding in any such country or British overseas territory shall be admissible in evidence;
(c)a document, duly authenticated, which certifies that a person was convicted on a date specified in the document of an offence against the law of, or of a part of, any such country or any British overseas territory shall be admissible as evidence of the fact and date of the conviction.
(2) A document shall be deemed to be duly authenticated for the purposes of this section—
(a)in the case of a document purporting to set out evidence given as mentioned in subsection (1)(a) above, if the document purports to be certified by a judge or magistrate or officer in or of the country or British overseas territory in question to be the original document containing or recording that evidence or a true copy of such a document;
(b)in the case of a document which purports to have been received in evidence as mentioned in subsection (1)(b) above or to be a copy of a document so received, if the document purports to be certified as mentioned in paragraph (a) above to have been, or to be a true copy of a document which has been, so received;
(c)in the case of a document which certifies that a person was convicted as mentioned in subsection (1)(c) above, if the document purports to be certified as mentioned in paragraph (a) above,
and in any such case the document is authenticated either by the oath of a witness or by the official seal of a Minister of the country or of the Governor or a Minister, secretary or other officer administering a department of the government of the British overseas territory, as the case may be.
(3) Nothing in this section shall prejudice the admission in evidence of any document which is admissible in evidence apart from this section.