13Custody review
(1)A custody review must be carried out—
(a)when a person has been held in police custody for a continuous period of 6 hours by virtue of authorisation given under section 7, and
(b)again, if authorisation to keep the person in police custody is given under section 11, when the person has been held in custody for a continuous period of 6 hours by virtue of that authorisation.
(2)A custody review entails the consideration by a constable of whether the test in section 14 is met.
(3)A custody review must be carried out by a constable who—
(a)is of the rank of inspector or above, and
(b)has not been involved in the investigation in connection with which the person is in police custody.
(4)If the constable is not satisfied that the test in section 14 is met, the person may continue to be held in police custody only if—
(a)a constable charges the person with an offence, or
(b)the person is detained under section 28(1A) of the 1995 Act (which allows for detention in connection with a breach of bail conditions).