False imprisonment claims are not limited to cases arising from an unlawful arrest. The tort covers the total deprivation of a person’s liberty without lawful authority, and can arise wherever a public authority has the power to detain someone, including the police, the Home Office in the immigration context, and the Ministry of Justice in relation to prisoners.

For solicitors handling this broader category of claim, and the costs lawyers and costs draftsmen supporting them, the false imprisonment costs recovery issues can differ meaningfully depending on which public authority is responsible and how the unlawful detention came about.

What Is False Imprisonment?

False imprisonment is generally treated as a strict liability tort. As the House of Lords confirmed in R v Deputy Governor of Pankhurst Prison, Ex parte Hague, the tort has two ingredients only: the fact of imprisonment, and the absence of lawful authority to justify it. Unlike a claim for wrongful arrest, which typically turns on whether an arresting officer’s suspicion and belief in the necessity of arrest were reasonable, a false imprisonment claim arising from detention beyond a lawful period does not generally require any finding of bad faith or fault on the part of the detaining authority.

This distinction matters for costs false imprisonment costs recovery purposes, since it can materially affect how quickly liability is conceded, and therefore how much of the costs incurred relate to establishing liability rather than quantifying the claim.

Beyond the Arrest: Other Contexts Where Claims Arise

Alongside claims connected to an unlawful arrest, false imprisonment claims against public authorities commonly arise from:

• Miscalculated release dates: In one leading case, a prisoner was detained 59 days beyond her correct release date due to a miscalculation of her sentence, and the House of Lords confirmed the detention was unlawful, awarding aggravated and exemplary damages given the circumstances.
• Detention beyond statutory custody time limits: Where a person on remand is held beyond the applicable custody time limit due to administrative failures, a false imprisonment claim may arise, though identifying the correct defendant can be more complex than it first appears, as discussed below.
• Immigration detention: Claims against the Home Office can arise where a person is detained under immigration powers for longer than can be lawfully justified, or where the decision to detain did not properly apply the relevant policy or legal tests.
• Detention under mental health legislation: Claims can arise where a person has been detained under the Mental Health Act without the proper legal or procedural basis for that detention having been satisfied.

Why Identifying the Correct Public Authority Matters for Costs

One instructive cautionary case involved a woman held 81 days beyond the statutory custody time limit due to failures attributed to the Crown Prosecution Service. Her claim for false imprisonment against the Home Office, and a related claim against the CPS, were both struck out on the basis that the prison governor was bound by the court warrant authorising her detention, and the relevant regulations did not create the private law rights needed to find a claim against the CPS in those circumstances.

This case is a useful reminder that identifying the public authority that actually held the legal power, or the legal responsibility, for a period of detention is a critical early step, not a formality. Costs incurred pursuing a claim against the wrong public authority, or on a legal basis that does not in fact exist, are unlikely to be recoverable, making this an area where early, careful analysis can materially reduce costs risk for both the client and the firm.

Damages and the Proportionality Challenge

General damages in false imprisonment claims are generally assessed by reference to the length and circumstances of the detention, with reference to the relevant guidelines used across personal injury and civil claims practice. Where the detaining authority’s conduct was particularly poor, for example where a miscalculation persisted despite an opportunity to identify it, aggravated or exemplary damages may also be available, as in the release-date miscalculation case referred to above.

Even so, for shorter periods of unlawful detention, the resulting damages can still be modest relative to the costs of investigating and proving the claim, particularly where the public authority in question disputes liability or the correct defendant is not immediately obvious. As with other actions against public authorities, proportionality is frequently raised by the paying party at detailed assessment, and a bill of costs that clearly explains the work involved in identifying liability, particularly in more complex multi-agency scenarios, tends to be better placed to resist that challenge.

What Tends to Be Disputed at Detailed Assessment

In addition to the general proportionality arguments common to actions against the police and public authorities, typically legal aid, subject to means and merits testing, or a conditional fee agreement. Given the strict liability nature of the tort, solicitors and costs practitioners should keep a clear record from the outset of the specific legal basis for detention being unlawful, and the reasoning for identifying a particular public authority as the correct defendant, since this analysis is often central to resisting both liability disputes and costs challenges later in the claim.

Speak to Greener Costs Today

 If you are a solicitor handling a false imprisonment claim against a public authority and would like support with funding advice, a costs budget, or preparing a bill of costs for detailed assessment, contact Greener Costs’ costs lawyers and costs draftsmen on 01204 263047 or info@greenercosts.co.uk.

FAQs – False Imprisonment Costs Recovery

Is false imprisonment the same as wrongful arrest?

Not quite. Wrongful arrest concerns whether the arrest itself was lawful under PACE. False imprisonment is broader, covering any period of unlawful detention by a public authority, including detention beyond a lawful release date or custody time limit.

Do I need to prove the public authority acted in bad faith?

Generally, no. False imprisonment is treated as a strict liability tort, meaning liability can arise even where the detaining authority acted in good faith, provided the detention lacked lawful authority.

Why does identifying the correct defendant matter so much in these claims?

Case law shows that claims brought against the wrong public authority, where legal responsibility in fact rested elsewhere, can be struck out, meaning costs incurred pursuing the wrong defendant are unlikely to be recoverable.