(1) Where -
(a) a substance has been seized under section 55 or 56, and
(b) there continue to be reasonable grounds to suspect that the substance was intended for use as a drug-cutting agent,
it may be retained until the end of the 30th day after the date of seizure.
(2) Where -
(a) a substance has been seized under another enactment and is lawfully in the possession of a police or customs officer,
(b) the period during which the substance may lawfully be retained under that enactment expires, and
(c) there are reasonable grounds to suspect that the substance was intended for use as a drug-cutting agent,
it may be retained until the end of the 30th day after the period referred to in paragraph (b).