89.— (1) The Garda Commissioner—

(a) shall ensure that members of the Garda Síochána, on becoming aware of a complaint, take any lawful measures that appear to them to be necessary or expedient for the purpose of obtaining and preserving evidence relating to the conduct that is the subject matter of the complaint, and

(b) may postpone notifying a member of the Garda Síochána whose conduct is the subject matter of the complaint until those measures are taken.

(2) Subsection (1) applies whether or not a determination has been made under section 87 about the admissibility of the complaint.