What Is Unlawful Detention and How to Claim Damages?

Being detained by the police is a serious interference with your freedom. While the police do have legal powers to arrest and detain individuals, those powers are not unlimited. When the police detain someone without proper legal authority, or keep them detained longer than the law allows, this may amount to unlawful detention.

Unlawful detention is often referred to interchangeably with unlawful arrest or wrongful arrest, and the legal principles behind these claims are closely linked. If you have been detained without lawful justification, you may be entitled to claim damages for the harm and distress you have suffered.

This guide explains what unlawful detention is, how it happens, and how to bring a claim against the police.

What is unlawful detention?

Unlawful detention occurs when the police deprive someone of their liberty without lawful authority or justification. In most cases, it arises where an arrest was unlawful from the outset, or where continued detention became unlawful after the initial arrest.

Under English law, the police must have both:

• Legal power to detain you, and
• A lawful reason for exercising that power.

If either of these is missing, the detention may be unlawful.

In practice, unlawful detention is commonly treated as the civil wrong of false imprisonment, part of the Criminal Justice and Public Order Act (1994), even if the detention lasts only a short period of time.

Is unlawful detention the same as unlawful arrest?

In many cases, yes. Unlawful detention is often used as another term for unlawful arrest or wrongful arrest.

An arrest is unlawful if:

• The police did not have reasonable grounds to suspect an offence
• Arrest was not necessary under the circumstances
• The officer failed to explain the reason for the arrest

Read in more detail some examples of unlawful arrest in our blog.

If the arrest itself was unlawful, any detention that follows is also unlawful. This can then be classed as false imprisonment or unlawful imprisonment, which can also result in compensation. 

However, detention can also become unlawful after a lawful arrest, for example, if:

• You are held longer than legally permitted
• The police fail to review your detention properly
• The justification for detention no longer applies
• Police do not follow the correct arrest procedures

Common examples of unlawful detention

Unlawful detention can arise in a wide range of situations, including:

• Arrest without reasonable suspicion
• Detention for questioning when you could have attended voluntarily
• Failure to carry out timely custody reviews
• Detaining someone after a decision has been made to release them
• Holding a person to “assist enquiries” without lawful grounds

Even a short delay in release can amount to unlawful detention if there is no legal justification for it. If any of the above has happened to you, you could be entitled to claim compensation for unlawful detention.

What rights do you have while detained by the police?

When you are detained, the police must comply with strict legal safeguards, primarily under the Police and Criminal Evidence Act 1984 (PACE). Your rights include:

• The right to be informed of the reason for your arrest and detention
• The right to free, independent legal advice
• The right to have someone informed of your detention
• The right to regular reviews of your detention
• The right to adequate rest, food, drink, and medical care
• The right to be released as soon as detention is no longer necessary

For more information about your rights when detained by police, read our recent blog.

What harm can unlawful detention cause?

Being unlawfully detained can have serious consequences, even if it lasts only a few hours. Many people experience:

• Anxiety, fear, and humiliation
• Damage to reputation or employment prospects
• Strain on family and personal relationships
• Physical injury or worsening of existing health conditions
• Long-term psychological effects

The law recognises that the loss of liberty is serious in itself, and compensation is available even where there is no lasting physical injury.

Can I claim damages for unlawful detention?

Yes. If you were unlawfully detained, you may be entitled to damages from the police.

A claim can include compensation for:

• Loss of liberty (the period you were detained)
• Distress and emotional harm
• Physical injuries, if force was used
• Aggravated damages, where police conduct was oppressive or humiliating
• Financial losses, such as lost earnings or expenses

The amount of compensation depends on the length and circumstances of the detention, as well as the impact it had on you. For more detail on typical compensation levels, you may find this guide helpful.

How do I claim damages for unlawful detention?

Bringing a claim against the police requires careful preparation. The key steps usually include:

1. Gathering evidence

This may include:

• Custody records and detention logs
• Medical records or photographs of injuries
• CCTV or body-worn camera footage
• Witness statements
• Your own written account of events

2. Legal assessment

A specialist solicitor will assess whether:

• The arrest and detention were lawful
• Police powers were properly exercised
• Any procedural failures occurred

3. Bringing a civil claim

Most unlawful detention claims are brought as civil actions against the relevant police force. These claims are often strongly defended, making experienced legal representation essential.

Do I need to complain to the police first?

You do not need to make a formal police complaint before claiming damages for unlawful detention.

A complaint may result in:

• An explanation or apology
• Internal disciplinary action

However, compensation can only be obtained through a civil claim, not through the complaints process alone.

What if I were charged or released under investigation?

Being charged, released under investigation, or even convicted does not automatically prevent an unlawful detention claim.

The key issue is whether the police acted lawfully at the time of arrest and during detention. If the legal threshold for arrest or continued detention was not met, you may still be entitled to damages.

Is there a time limit for unlawful detention claims?

Yes. Time limits apply and can be strict:

• Unlawful detention and false imprisonment claims must be brought within six years
• Claims involving human rights breaches usually have a one-year time limit

Because different time limits can apply at the same time, early legal advice is strongly recommended.

HNK Solicitors can help you claim damages for unlawful detention

At HNK Solicitors, we specialise in claims against the police, including unlawful detention, unlawful arrest, and false imprisonment. We understand how intimidating it can feel to challenge police conduct, and we are committed to protecting your rights.

We can:

• Assess whether your detention was unlawful
• Explain your options clearly and honestly
• Handle all correspondence with the police
• Pursue maximum compensation on your behalf
• Act on a no-win, no-fee basis, where appropriate

If you believe you were unlawfully detained, contact HNK Solicitors today for free,confidential advice. Call us on 0151 668 0809 or email enquiries@hnksolictors.com. We are here to help you hold the police accountable and secure the damages you deserve.