Where in any proceedings the fact that a person has in the United Kingdom ... been convicted or acquitted of an offence otherwise than by a Service court is admissible in evidence, it may be proved by producing a certificate of conviction or, as the case may be, of acquittal relating to that offence, and proving that the person named in the certificate as having been convicted or acquitted of the offence is the person whose conviction or acquittal of the offence is to be proved.
For the purposes of this section a certificate of conviction or of acquittal—
and a document purporting to be a duly signed certificate of conviction or acquittal under this section shall be taken to be such a certificate unless the contrary is proved.
In subsection (2) above "proper officer" means—
The method of proving a conviction or acquittal authorised by this section shall be in addition to and not to the exclusion of any other authorised manner of proving a conviction or acquittal.