(1)  The Commissioner must appoint one or more police officers as custody officers for each designated police station.

(2)  A police officer who is below the rank of sergeant may not be appointed as a custody officer for a designated police station unless there is no person of that rank or above that rank deployed at the designated police station.

(3)  A police officer of any rank may perform the functions of a custody officer at a designated police station if a custody officer is not readily available to perform them.

(4)  Subject to subsections (5) and (6) and section 16 (3) , none of the functions of a custody officer in relation to a person are to be performed by a police officer who at the time the function is to be performed is involved in the investigation of an offence for which that person is in custody at that time.

(5)  Nothing in subsection (4) is to be taken to prevent a custody officer –

(a) doing anything in connection with the identification of a suspect; or

(b) doing anything under the Road Safety (Alcohol and Drugs) Act 1970 or Marine Safety (Misuse of Alcohol) Act 2006 .

(6)  Where a person in custody is taken to a police station which is not a designated police station, the functions in relation to that person which at a designated police station would be the functions of a custody officer are to be performed –

(a) by a police officer who is not involved in the investigation of an offence for which that person is in custody, if such an officer is readily available; and

(b) if no such police officer is readily available, by the officer who took the person to the station or any other officer.

(7)  References to a custody officer in sections 15 and 16 include references to a police officer other than the custody officer who is performing the functions of a custody officer by virtue of subsection (3) or (6) .