The treatment of persons in police detention is governed by the Police and Criminal Evidence Act 1984 (PACE) Code C. A suspect under arrest can generally be detained in custody for a maximum of 24 hours. However, when the offence is indictable and it has been authorised by a magistrates' court, detention can be up to 96 hours. Extended time limits apply to those suspected of terrorism, which are not considered in this post.
Time spent on bail does not count towards the time a person spends in police detention (Police (Detention and Bail) Act 2011).
On arrival at a police station, a custody officer will determine whether there is sufficient evidence to charge the suspect with the offence. If the officer decides there is insufficient evidence to charge, but there are reasonable grounds for believing that detention is necessary to secure or preserve evidence or to obtain evidence by questioning, then the following timeline is followed.
What happens when the timeline is not followed?
In Roberts v Chief Constable of the Cheshire Constabulary  1 WLR 62, it was held that a failure to review at the times above renders a previously lawful detention unlawful. It amounts to false imprisonment.
False imprisonment means the total restraint of a person's liberty for any duration and without lawful justification. The claimant must prove that the detention was justified (Hicks v Faulkner  8 QBD 167). The restraint does not need to be physical. For example, where someone is led to believe they are obliged to remain this will be enough (Warner v Riddiford  4 CBNS 180).
There is no minimum period of detention for a claim to succeed. However, in cases where the review process above has not been followed, the claimant will need to prove that there was more than a trivial delay. In Roberts, a delay of 2 hours and 20 minutes was deemed to be sufficient to result in an unlawful detention.
Claims can be made up to 6 years from the date of detention.