69Power of arrest in anticipation of commission of service offenceE+W+S+N.I.
(1)A service policeman may arrest a person whom he reasonably suspects of being about to commit a service offence.
(2)Subsection (6) of section 67 applies in relation to the power of arrest conferred by this section as it applies in relation to the power of arrest conferred by that section.
(3)Where a person is arrested under this section—
(a)the arrest must be reported as soon as practicable to his commanding officer; and
(b)he may be kept in service custody until such time as a service policeman is satisfied that the risk of his committing the service offence concerned has passed.