How Private Investigators Help Solicitors in the UK

June 28, 2021 - Reading time: 7 minutes
Updated on: August 7, 2025

Private investigators can be hired by members of the public under many different circumstances, from investigating cheating partners to catching fly-tippers. However, private investigators also work closely with law firms and often receive instructions directly from solicitors on a wide range of legal matters.

Such is the value of private investigators to the legal sector that some solicitors in the UK rely on PIs in nearly every case they handle [source]. Below are some of the key services provided by private investigators that assist solicitors in civil, family, and criminal law cases.

1. Injury claim investigations

Personal injury investigations are one of the most common reasons solicitors hire private investigators. If someone is claiming to be unable to walk unaided, yet is seen playing football by a PI, that evidence can significantly weaken their case. In many situations, the claimant may drop their case entirely once confronted with surveillance footage or photographic evidence.

This type of evidence gathering helps law firms save time and money by avoiding lengthy and unnecessary litigation.

2. Process serving (legal document delivery)

Solicitors regularly need legal documents served on individuals or businesses. Hiring a private investigator as a process server ensures that documents are delivered properly, within legal guidelines, and with proof of service.

Common documents served by PIs in the UK include:

• Winding-up petitions
• Divorce petitions
• Bankruptcy papers
• Statutory demands
• Prohibition orders
• License applications

This service is especially useful when recipients are evasive or difficult to locate.

3. Support with divorce and family law cases

In divorce cases involving infidelity, hidden assets or child custody disputes, private investigators help gather evidence to support a solicitor’s case. The average divorce in the UK costs over £14,000 in legal and lifestyle costs, and the stakes can be far higher when property or business interests are involved.

Clear evidence of cheating or financial misconduct can be critical in achieving a fair settlement.

4. Tracing people and debtors

Private investigators are skilled in locating missing persons, evasive debtors, or former clients who have disappeared. Solicitors may need to trace individuals before initiating proceedings, serving documents, or enforcing court judgments.

Using public record searches, surveillance, social engineering, and proprietary databases, PIs can often locate subjects who are actively avoiding contact.

5. Interviewing witnesses or gathering statements

Interviewing witnesses or character references is another area where solicitors benefit from hiring a private investigator. In cases involving personal injury, fraud, or workplace incidents, PIs can collect statements or evidence that supports the solicitor’s legal strategy.

Hiring a PI can also reduce costs, as their fees are typically lower than those of qualified legal professionals.

6. Lie detector testing (polygraph services)

Polygraph testing is sometimes used to resolve disputes, clarify allegations, or support legal strategies in family or civil cases. Although lie detector results are not typically admissible in court, they can be used by solicitors as supporting material or to guide negotiations.

Private investigators who are trained in polygraph testing may conduct these exams in private residences or solicitor’s offices.

7. Locating hidden assets

Solicitors often instruct PIs to help trace assets that a person may be trying to conceal. This is particularly useful in divorce settlements, debt recovery cases, or business disputes where one party may be attempting to hide income, property, or other financial holdings.

Asset tracing helps ensure a fair and transparent outcome in legal proceedings.

8. Intellectual property investigations

Private investigators support solicitors in identifying and proving cases of intellectual property theft. This could involve tracking down counterfeit goods, identifying rogue suppliers, or collecting evidence of unauthorised brand use.

Evidence gathered by PIs can help build strong IP cases for court or settlement negotiations.

9. Social media and online investigations

Private investigators are frequently hired to conduct deep dives into a subject’s online presence. Social media platforms, forums, and other digital footprints can reveal useful information about behaviour, character, lifestyle, and associations.

Such evidence can support civil claims, background checks, family law matters, and more.

10. Background checks for due diligence

Whether a solicitor is working on a merger, hiring case, or business partnership vetting, private investigators can help conduct thorough background checks on individuals or companies. This ensures no surprises arise down the line and helps mitigate reputational or financial risk.

Due diligence investigations are especially valuable before signing contracts or entering legal agreements.

Work With PrivateInvestigators‑UK

These are just some of the ways solicitors in the UK rely on private investigators to support legal matters. From court-compliant surveillance and document delivery to witness interviews and asset tracing, private investigators can help strengthen your legal case and ensure a smoother process for clients.

PrivateInvestigators-UK is a trusted agency offering legal investigation services across the UK and internationally. Visit our homepage to learn more, or explore the rest of our blog for additional resources.

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