21.—(1) Subject to paragraph (3), in any proceedings for an Article 4(1) offence or a regulation 13 offence, it is a defence for the accused to prove that the accused neither knew of nor suspected nor had reason to suspect the existence of some fact alleged by the prosecution that it is necessary to prove if the accused is to be convicted of the offence charged.
(2) Paragraph (3) applies where, in any proceedings for an Article 4(1) offence or a regulation 13 offence—
(a)it is necessary, if the accused is to be convicted of the offence charged, for the prosecution to prove that some substance or mixture involved in the alleged offence was the tier 2 substance that the prosecution allege it to have been, and
(b)it is proved that the substance or mixture in question was that tier 2 substance.
(3) Where this paragraph applies—
(a)the accused must not be acquitted of the offence charged by reason only of proving that the accused neither knew nor suspected nor had reason to suspect that the substance or mixture was the particular tier 2 substance alleged, but
(b)the accused must be acquitted of the offence charged if—
(i)the accused proves that the accused neither believed nor suspected nor had reason to suspect that the substance or mixture was a tier 2 substance, or
(ii)the accused proves that the accused believed the substance or mixture to be a tier 2 substance such that, if it had in fact been that tier 2 substance, the accused would not at the material time have been committing any offence to which this regulation applies.
(4) In this regulation—
“an Article 4(1) offence” means an offence under Article 31 of the 1978 Order for a contravention of Article 4(1) of the Precursors Regulation (by virtue of regulation 18); and
“a regulation 13 offence” means an offence under Article 31 of the 1978 Order for a contravention of regulation 13.