79. (1) Subject to subsection (2), a sample taken from a person under section 11 , 31, 32 or 34 shall, if not previously destroyed, be destroyed—

(a) as soon as a DNA profile has been generated from the sample, or

(b) before the expiration of the period of 6 months from the taking of the sample,

whichever occurs later.

(2) If the Commissioner is satisfied that exceptional circumstances exist that justify the destruction of a sample taken from a person under section 11 , the sample shall, if not previously destroyed, be destroyed as soon as practicable after the application of those circumstances in relation to the sample becomes known.

(3) The exceptional circumstances referred to in subsection (2)are the following:

(a) it is established, at any time after the detention of the person concerned under any of the provisions referred to in section 9(1)for the purposes of the investigation of a relevant offence during which the sample concerned was taken, that no such offence was committed;

(b) it is established that the detention of the person concerned under any of the provisions referred to in section 9(1)for the purposes of the investigation of a relevant offence during which the sample concerned was taken was on the basis of the mistaken identity of the person concerned as the perpetrator of that relevant offence; or

(c) it is determined by a court that the detention of the person concerned under any of the provisions referred to in section 9(1) for the purposes of the investigation of a relevant offence during which the sample concerned was taken was unlawful.