The Importance of Lawfully Obtaining Evidence
Recent High Court proceedings have highlighted a fundamental principle of the criminal justice system: regardless of the nature of the allegations or the profile of the individual involved, police investigations must be carried out lawfully.
It has been widely reported that Thames Valley Police accepted that search warrants used to search the properties of Andrew Mountbatten-Windsor were issued under an incorrect legal basis and should therefore be quashed. While the police investigation remains ongoing, the case serves as an important reminder of the safeguards that exist to protect the rights of individuals subject to criminal investigations.
Why Were the Search Warrants Challenged?
According to reports of the High Court proceedings, search warrants were issued in February 2026 as part of an investigation into allegations of misconduct in public office.
Following the execution of those warrants, documents and electronic devices were seized from properties linked to Andrew Mountbatten-Windsor. His legal team subsequently challenged the lawfulness of the warrants through judicial review proceedings.
During those proceedings, Thames Valley Police accepted that the warrants had been obtained using the wrong legal basis and agreed that they should be quashed. However, the force maintains that the underlying investigation continues and that the issue relates to the legality of the searches rather than the substance of the allegations themselves.
Further legal proceedings are reportedly considering whether the material obtained during those searches can continue to be retained by investigators.
What Is Due Process?
Due process is a cornerstone of the criminal justice system. It requires police officers, prosecutors and courts to act in accordance with established legal rules and procedures when investigating and prosecuting criminal offences.
These protections arise from legislation, common law and fundamental rights, including the right to a fair trial and the right to respect for private and family life.
Importantly, these requirements are not mere technicalities. They exist to ensure that significant investigative powers are exercised lawfully, proportionately and subject to proper independent scrutiny.
An individual does not lose these protections simply because they have been accused of a criminal offence, however serious the allegation may be.
Why Do Police Require Lawful Search Warrants?
Police possess extensive powers to investigate suspected criminal activity. However, entering private premises and seizing property generally requires a recognised legal authority.
That authority may arise through:
- A lawfully obtained search warrant;
- A specific statutory power to search without a warrant; or
- The valid consent of the occupier.
Where a warrant is required, strict legal criteria must be satisfied before it can be issued. These safeguards help ensure that searches are justified, proportionate and carried out through the correct legal process.
Search warrants can permit police officers to access highly sensitive material, including personal correspondence, confidential documents, computers, mobile phones and large volumes of private information. The legal safeguards surrounding search warrants therefore protect not only property rights but also privacy, confidentiality and the interests of individuals who may have no involvement whatsoever in any alleged criminality.
Does an Unlawful Search Mean the Evidence Cannot Be Used?
Not necessarily.
One of the most misunderstood aspects of criminal law is that evidence obtained unlawfully is not automatically excluded from criminal proceedings.
Where a search warrant is subsequently found to be unlawful, a number of important questions may arise, including:
- Whether seized property should be returned;
- Whether investigators can continue to retain the material obtained; and
- Whether any evidence derived from that material can be relied upon in subsequent criminal proceedings.
Under section 78 of the Police and Criminal Evidence Act 1984, a court has the discretion to exclude prosecution evidence where its admission would have such an adverse effect on the fairness of the proceedings that it ought not to be admitted.
This does not create an automatic rule of exclusion. Instead, the court must carefully examine all the circumstances of the particular case before deciding whether evidence should be admitted.
It is also important to distinguish between judicial review proceedings, which examine the lawfulness of police actions, and criminal proceedings, which determine whether a defendant is guilty of a criminal offence. They involve different legal issues and serve different purposes.
Can an Investigation Continue Following an Unlawful Search?
Yes.
The fact that a warrant has been quashed does not automatically bring a criminal investigation to an end.
Investigators may still have access to other lawful lines of enquiry and the consequences of any unlawfully obtained material will depend on the relevant legal framework and the decisions of the courts.
In the Andrew Mountbatten-Windsor matter, the reported position is that the investigation remains ongoing while the courts determine issues relating to the material seized during the searches.
It is important to note that the finding regarding the warrants does not amount to a determination of guilt or innocence in relation to the underlying allegations.
Why Due Process Protects Everyone
Cases that attract significant public attention often prompt strong opinions. However, due process exists to protect everyone equally.
These legal safeguards:
- Protect individuals from unjustified state interference;
- Allow unlawful investigative conduct to be challenged;
- Help ensure that criminal proceedings are conducted fairly; and
- Promote public confidence in both policing and the courts.
The scrutiny of police powers by independent courts is a vital component of the rule of law. When mistakes are identified and corrected, it demonstrates that those safeguards are functioning as intended.
The principle is simple: the seriousness of an allegation does not remove the obligation to investigate it lawfully.
Challenging Police Powers and Protecting Your Rights
For individuals facing a criminal investigation, the lawfulness of a search, arrest or seizure of property can be a significant issue.
Experienced criminal defence solicitors will carefully examine:
- The statutory powers relied upon by investigators;
- The information used to obtain any warrant;
- The scope and execution of the search; and
- The handling and retention of seized material.
Where appropriate, legal challenges can be brought through the relevant procedures, although the remedies available will depend on the circumstances of each case.
How Tank Jowett Solicitors Can Help
At Tank Jowett Solicitors, we represent clients at every stage of a criminal investigation, from police station interviews through to proceedings in the Magistrates’ Court, Crown Court and appellate courts.
Our experienced criminal defence team regularly advises on cases involving:
- Search warrants;
- Police powers of entry and seizure;
- Judicial review challenges;
- Disclosure issues;
- Admissibility of evidence; and
- Serious and complex criminal investigations.
The wider lesson from the Andrew Mountbatten-Windsor case is that due process is not a privilege afforded to a select few. It is a fundamental safeguard designed to protect everyone, regardless of their background, reputation or the nature of the allegations they face.
Contact Tank Jowett Solicitors
If you are under investigation or have concerns regarding the legality of a search, arrest or seizure of property, our specialist criminal defence solicitors can provide expert advice and representation.
Contact Tank Jowett Solicitors today for confidential legal advice and assistance.