(1)An item seized under section 21 or 23 may be retained for as long as is necessary in all the circumstances and in particular—
(a)for use as evidence at a trial for a relevant offence, or
(b)for forensic examination or for investigation in connection with a relevant offence.
(2)An item may be not be retained for either of the purposes mentioned in subsection (1) if a photograph or a copy would be sufficient for that purpose.