Where you suspect that a false allegation has been made against you should get legal advice immediately as in some cases a police arrest can be avoided.
An arrest can have far-reaching repercussions in relation to travel, your career or even volunteer work.
Case law is clear that a voluntary attendance should be considered by officers where there is no urgency surrounding the investigation but police officers often maintain that an arrest is "necessary" under the frequently used terms of PACE, s.24(5)(e): "to allow the prompt and effective investigation of the offence or of the conduct of the person in question."
The requirement of 'necessity' as laid down by Parliament is, however, often not, on any realistic interpretation of the word, met.
Police officers often put forward various reasons as to why an arrest is necessary: the possible risk of destruction or concealment of evidence, the possibility of the accused seeking to make contact with "co-suspects" etc but these reasons must be justified.
The test of the validity of an arrest has been set out by the Court of Appeal in Hayes v. Chief Constable of Merseyside Police  1 WLR 517.
A constable must believe that the arrest is necessary and that objectively the belief was reasonable. Merely theoretical concerns are not enough, and whilst an officer is not required to interrogate the suspect to determine whether they will attend a police station voluntarily to be interviewed they must consider whether the suspect’s voluntary attendance is a practicable alternative for carrying out the interview.
If it is, then an arrest would not be necessary and representations to that effect can be made on your behalf.