If a thing has been seized but not forfeited, the authorised person must return it to its owner—
(a) for a thing seized under section 404 —(i) at the end of 6 months; or(ii) if a proceeding for an offence involving the thing is started within 6 months, at the end of the proceeding and any appeal from the proceeding; or(iii) if the authorised person stops being satisfied its continued retention as evidence is necessary—immediately; or
(b) for a thing seized under section 405 if—(i) the thing ceases to be a public health risk; or(ii) the authorised person is satisfied the return of the thing is unlikely to result in the recurrence of the public health risk in relation to which it was seized.