PART 3 - GENERAL PROVISIONS RELATING TO REQUESTS FOR ASSISTANCE
26.
Urgent requests—
(1)In urgent cases a request for assistance (including a request for provisional arrest) may be—
(a)made using any medium capable of delivering a written record:
(b)transmitted through the International Criminal Police Organisation or any other appropriate regional organisation, instead of through an authorised channel.
(2)If a request is made or transmitted in the first instance in the manner specified in subsection (1), it must be followed as soon as practicable by a formal request transmitted in the manner specified in section 25.
Provisional arrest
Cooperation of State
Unique provision - cooperation
EDIT.