Section 71: Evidence by certificate.

Where in any proceedings for an offence under this Act, a question arises as to whether anything or substance is a weapon, hazardous, radioactive or harmful substance, a toxic chemical, microbial or other biological agent or toxin, a certificate purporting to be signed by an appropriate authority to the effect that the thing or substance described in the certificate is a weapon, hazardous, radioactive or harmful substance, a toxic chemical, microbial or other biological agent or toxin, shall—(a) be admissible in evidence without proof of the signature of the person appearing to have signed it; and
(b) in the absence of evidence to the contrary, be proof of the facts stated in the certificate.