'(1) The report required by section [Power to declare reserve power exercisable] (2)(b) is a report by—

(a) the Director of Public Prosecutions and the chief officer of a police force in England and Wales,

(b) the Crown Agent and the chief constable of a police force in Scotland, or

(c) the Director of Public Prosecutions for Northern Ireland and the Chief Constable of the Police Service of Northern Ireland,

to the following effect.

(2) The report must—

(a) state that each of the persons making the report is satisfied that there are reasonable grounds for believing that the detention of one or more persons beyond 28 days will be necessary for one or more of the purposes mentioned in subsection (3) below, and

(b) give details of the grounds for that belief.

(3) The purposes referred to in subsection (2)(a) are—

(a) to obtain, whether by questioning or otherwise, evidence that relates to the commission by the detained person or persons of a serious terrorist offence,

(b) to preserve such evidence, or

(c) pending the result of an examination or analysis of any such evidence or of anything the examination or analysis of which is to be or is being carried out with a view to obtaining such evidence.

(4) In subsection (3)(a) a "serious terrorist offence" means—

(a) an offence under the Terrorism Act 2000 (c. 11) or the Terrorism Act 2006 (c. 11), or

(b) any offence that has a terrorist connection,

in respect of which an offender who has attained the age of 21 (in England and Wales, 18) is liable on conviction to a sentence of imprisonment for life.

(5) The report must also state that each of the persons making the report is satisfied that the investigation in connection with which the detained person or persons is or are detained is being conducted diligently and expeditiously.

(6) Until the coming into force of section 61 of the Criminal Justice and Court Services Act 2000 (c. 43) (abolition of sentences of custody for life etc), subsection (4) has effect with the omission of the words "(in England and Wales, 18)".'.