kept in prison for 59 days longer that she should have been as a result of the governor mis-calculating the length of the term that she was to serve in light of time spent on remand. In so doing the governor had acted in accordance with what was thought by the Home Office and the Courts to be the correct legal approach at the time. In ex parte Evans the Divisional Court overruled that earlier approach and upheld the case in false imprisonment and awarded compensation. The House of Lords upheld the decision on liability (and agreed that the Court of Appeal were correct to increase the compensation award):
“…for the governor to escape liability for any extended period of detention on the basis that he was acting honestly or on reasonable grounds analogous to those which apply to arresting police officers would reduce the protection currently provided by the tort of false imprisonment. I can see no justification for limiting the application of the tort in this way. The authorities are at one in treating it as a tort of strict liability. That strikes the right balance between the liberty of the subject and the pubic interest in the detection and punishment of crime. The defence of justification must be based upon a rigorous application of the principle that the liberty of the subject can be interfered with only upon grounds which a court will uphold as lawful” (Lord Hope at 35D-E)11.
7.Equally it is no defence for a defendant to show that although the detention was not undertaken in accordance with the relevant power, the claimant could have been lawfully detained in the circumstances. This was confirmed in Roberts v Chief Constable of Cheshire12 in a case where detention at a police station in purported pursuance of the provisions of Part IV of the Police and Criminal Evidence Act 1984 (“PACE”) became unlawful because of the failure to carry out a review of the detention as prescribed by the statute. The fact that, if the review had been conducted, detention could have been lawfully continued did not provide a defence to the claim.
8.The majority of false imprisonment claims have arisen in the context of arrests made by the police (or other bodies with investigative powers). In cases of arrest without warrant the three central questions to be addressed are:
11 To similar effect see 42F. In that case the sentencing Court had not fixed the actual period that the claimant was to serve; the position is distinct where the defendant acts pursuant to a court order or a byelaw (unless it is on its face unlawful): see 35C & 46A-E. In Olotu v Home Office  1 WLR 328 a claim for false imprisonment failed as although the Crown Prosecution Service had failed to comply with the Prosecution of Offences (Custody Time Limits) Regulations 1987 the prison governor was under a duty to detain her until the Crown Court ordered her release.
12  1 WLR 662 CA.