PART III—GENERAL PROVISIONS RELATING TO REQUESTS FOR ASSISTANCE
22. (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; or
(b) transmitted through the International Criminal Police Organisation or any other appropriate regional organisation, instead of through an authorised channel (as defined in section 21).
(2) If a request is made or transmitted in the first instance in the manner specified in subsection (1), it shall be followed as soon as practicable by a formal request transmitted in the manner specified in section 21.
EDIT.