6(1)This paragraph applies where—
(a)authorisation is given under paragraph 4 for a travel document relating to a person to be retained, and
(b)the document is still being retained by a constable at the end of the period of 72 hours beginning when the document was taken from the person (“the 72-hour period”).
(2)A police officer who is—
(a)of at least the rank of chief superintendent, and
(b)of at least as high a rank as the senior police officer who gave the authorisation,
must carry out a review of whether the decision to give authorisation was flawed.
(3)The reviewing officer must—
(a)begin carrying out the review within the 72-hour period,
(b)complete the review as soon as possible, and
(c)communicate the findings of the review in writing to the relevant chief constable.
(4)The relevant chief constable must consider those findings and take whatever action seems appropriate.
(5)If a power under paragraph 2 was exercised in relation to the travel document by an immigration officer or customs official designated under paragraph 17, the reviewing officer must also communicate the findings of the review in writing to the Secretary of State.
(6)In this paragraph—
“reviewing officer” means the officer carrying out a review under this paragraph;
“relevant chief constable” means—
(except where paragraph (b) or (c) applies) the chief officer of police under whose direction and control is the constable retaining the document;
the chief constable of the Police Service of Scotland, if the constable retaining the document is under that chief constable’s direction and control;
the chief constable of the Police Service of Northern Ireland, if the constable retaining the document is under that chief constable’s direction and control.