An extract conviction of any crime committed in any part of the United Kingdom, bearing to be under the hand of the officer in use to give out such extract conviction, shall be received in evidence without being sworn to by witnesses.

It shall be competent to prove by a witness or witnesses such previous conviction, or any facts relevant to the admissibility of the same, although the name of any such witness is not included in the list served on the accused; and the accused shall be entitled to examine witnesses in regard thereto.

An official of any prison in which the accused may have been confined on such conviction shall be a competent and sufficient witness to prove the application thereof to the accused, although he may not have been present in court at the trial to which such conviction relates.