The National Crime Squad (Dispensation from Requirement to Investigate Complaints) Regulations 2003

4.—(1) For the purposes of regulation 3 it shall not be reasonably practicable to complete the investigation of a complaint if, and only if, in the opinion of the appropriate authority or, as the case may be, of the Authority, the circumstances in sub-paragraphs (2) or (3) apply.

(2) It is not reasonably practicable to communicate with the complainant or, as the case may be, the person who submitted the complaint, or any other injured person, notwithstanding that the complaint is not an anonymous one within the meaning of paragraph 2.

(3) It is not reasonably practicable to complete a satisfactory investigation in consequence of—

(a) a refusal or failure, on the part of the complainant, to make a statement or afford other reasonable assistance for the purposes of the investigation, or

(b) a refusal or failure, on the part of an injured person other than the complainant, to support the complaint, evidenced either by a statement in writing (signed by him or by his solicitor or other authorised agent on his behalf) to the effect that he does not support it or by a refusal or failure, on his part, such as is mentioned in sub-paragraph (a) above, or

(c) the lapse of time since the event or events forming the subject matter of the complaint.