7.—(1) In any proceedings under Article 31, a certificate signed by or on behalf of a Minister of the Crown or a Northern Ireland department and certifying that any conditions or requirements specified in the certificate—N.I.
(a)were imposed by that Minister or that department (as the case may be), and
(b)were in operation at a time or throughout a time so specified,
is conclusive evidence of the matters certified.
(2) A document purporting to be such a certificate is to be—
(a)received in evidence; and
(b)deemed to be such a certificate unless the contrary is proved.