When a previous conviction may be proved under any provision of this Act, a record, photograph or document which relates to a finger-print and which purports to emanate from the officer commanding the South African Criminal Bureau or, in the case of any other country, from any officer having charge of the criminal records of the country in question, shall, whether or not such record, photograph or document was obtained under any law or against the wish or the will of the person concerned, be admissible in evidence at criminal proceedings upon production thereof by a police official having the custody thereof, and shall be prima facie proof of the facts contained therein.