24 July 2026

Why Due Diligence Matters Before Instructing a Private Investigator

Why Due Diligence Matters Before Instructing a Private Investigator

I recently wrote for The Law Society about an issue that deserves greater attention: the due diligence solicitors should carry out before instructing a private investigator.

Choosing the wrong investigator can expose a law firm and its client to serious legal, regulatory, financial and reputational risk.

A recommendation, polished website or confident conversation may create a positive first impression, but none of those things proves that an investigator operates lawfully, protects sensitive information or has the experience required for the matter.

Responsibility begins before the first instruction is issued.

Why the appointment matters

When a solicitor instructs an investigator, that person may handle:

  • Confidential client information.
  • Personal data.
  • Sensitive allegations.
  • Financial records.
  • Litigation material.
  • Information relating to children or vulnerable people.
  • Evidence that may later be relied upon in court.

Poor practice can have consequences far beyond an unsuccessful assignment.

Improperly obtained information may be unusable. Sensitive data may be mishandled. The client’s position may be damaged, and the instructing firm may face difficult questions about the checks completed before the appointment.

That is why investigator selection should be treated as a professional-risk decision rather than a simple purchasing exercise.

A recommendation is not enough

Personal recommendations are useful, but they should be the beginning of the verification process rather than the end.

Before issuing instructions, solicitors should establish:

  • Whether the investigator belongs to a recognised professional body.
  • Whether their experience is relevant to the specific assignment.
  • How personal and confidential information will be protected.
  • Whether appropriate insurance is in place.
  • What governance and quality-control procedures apply.
  • Whether the proposed methods comply with relevant laws and regulations.
  • How the work will be documented.
  • Whether the resulting evidence is likely to withstand legal scrutiny.

The depth of the checks should reflect the sensitivity and complexity of the matter.

An investigator suitable for a straightforward tracing enquiry may not have the expertise required for a complex cross-border fraud, matrimonial dispute or high-value litigation matter.

Professional standards should be verified

The private-investigation sector includes highly experienced and accountable professionals, but standards cannot simply be assumed.

Membership of a recognised professional organisation can provide an additional level of assurance.

I currently serve as President of the Association of British Investigators, which promotes professional standards and requires members to meet defined criteria.

ABI accreditation can help solicitors identify providers who have been independently vetted and remain subject to professional accountability.

Accreditation should not replace a firm’s own due diligence, but it is an important part of the overall assessment.

Information security must form part of the review

Investigative work frequently involves highly sensitive information.

A firm should understand:

  • Where information will be stored.
  • Who will have access to it.
  • How material will be transferred.
  • Whether appropriate technical safeguards are in place.
  • How long records will be retained.
  • Whether subcontractors or overseas personnel may be involved.
  • What happens if a security incident occurs.

An investigator may be experienced in fieldwork while lacking the governance needed to protect digital records properly.

Solicitors should therefore assess information security alongside operational capability.

The proposed methodology should be clear

Before work begins, the investigator should be able to explain the proposed approach in understandable terms.

The instruction should define:

  • The objective of the work.
  • The lawful methods available.
  • The limits of the assignment.
  • The anticipated reporting format.
  • The likely timescale.
  • The fee structure.
  • Any foreseeable legal or ethical risks.
  • The circumstances in which further authority will be required.

Vague assurances should not replace a clearly defined scope.

A professional investigator should also be prepared to explain what cannot lawfully or realistically be achieved.

Evidence must be capable of scrutiny

The value of investigative work often depends on whether the findings can be explained, supported and challenged.

A report should distinguish between:

  • Verified facts.
  • Information obtained from third-party sources.
  • Open-source material.
  • Professional assessment.
  • Unconfirmed intelligence.
  • Evidential limitations.

Where material may be used in litigation, the investigator’s notes, methodology and source handling may become important.

The question is not simply whether information has been found. It is whether the work has been conducted in a way that protects the client and supports the legal strategy.

Due diligence protects everyone involved

A proper selection process protects:

  • The client.
  • The instructing solicitor.
  • The integrity of the evidence.
  • The reputation of the law firm.
  • The investigator carrying out the work.
  • The fairness of the legal process.

It also helps ensure that expectations are realistic from the outset.

Investigators should not promise guaranteed results, access to protected databases or methods they cannot properly explain.

Where claims sound too good to be true, they usually require closer examination.

Read the full Law Society article

My full article, “Due diligence begins before you pick up the phone,” is available on The Law Society website.

It examines the practical checks solicitors should complete before instructing an investigator and why professional accountability matters.

Read the full article on The Law Society website

About my work

I have worked in private investigation, corporate intelligence and complex cross-border matters for more than 25 years.

As co-founder and CEO of Conflict International, I work with law firms, businesses and private clients requiring discreet, compliant and professionally managed support.

My role as President of the Association of British Investigators also allows me to contribute to the continued development of professional standards across the sector.

Solicitors should be able to instruct an investigator with confidence, knowing that the person acting on their behalf has been properly assessed, operates lawfully and understands the responsibility that comes with handling sensitive client matters.

World Association of Detectives Association of British Investigators