An internal investigation starts tomorrow. Is your organisation ready?

A whistleblowing report arrives. There is a suspicion of fraud, misuse of confidential information or another potential breach of internal rules. HR, Compliance or Legal needs to understand what happened, and quickly.

For many organisations, the natural next step would be to start gathering information, interview the people involved and establish the facts.

But there is now another question that should be asked before the investigation begins: Does the Belgian Private Investigation Act apply, and is the organisation prepared for it?

This question is becoming particularly important as 16 December 2026 approaches.

A new reality for workplace investigations

The Belgian Act of 18 May 2024 regulating private investigation activities, commonly referred to as the Private Investigation Act (PIA/WPO), has been largely applicable since 16 December 2024.

Its impact goes further than the term “private investigation” might initially suggest. The legislation is not relevant only when a company hires a traditional private investigator. Depending on the circumstances, investigations conducted within an organisation may also fall within its scope.

Think, for example, about allegations concerning fraud, theft, breaches of company rules, misuse of confidential information or other misconduct potentially leading to disciplinary measures. These are situations in which organisations may need to establish facts about the conduct of individual employees.

And that is where Article 65 becomes particularly important.

Article 65: Should the investigation start with the investigation?

Article 65 introduces an important principle for investigations involving employees.

Employers wishing to conduct private investigations need an explicit and transparent internal framework addressing the possibility of such investigations and the rules governing them. Employees must therefore be informed in advance that private investigations may take place and under which rules and procedures they can be conducted.

In other words, organisations should not wait until a serious allegation lands on someone’s desk to decide how an investigation will work.

The framework should be established before the need for an investigation arises.

That means considering questions such as:

• When can an internal investigation be initiated?
• Who is authorised to conduct or support it?
• What investigative methods may be used?
• What safeguards apply to the employees concerned?
• How will personal data and information collected during the investigation be handled?
• How does the investigation process interact with existing HR, whistleblowing, compliance and privacy procedures?

The Act itself does not prescribe one exact form or content for that framework, so organisations need to determine an approach appropriate to their structure and investigation activities.

“But we don't have a private investigation department”

This is where the legislation can become less intuitive. An organisation may think the PIA is irrelevant because it does not employ private investigators or have a dedicated investigations team.

The reality requires a closer look.

The position is relatively clear where investigations are structurally carried out by an internal investigation service or assigned to external private investigators. The position can be more nuanced for occasional or ad hoc investigations conducted by functions such as HR that do not constitute an internal investigation service. Importantly, however, a one-off investigation does not automatically fall outside the Act.

At the same time, not every HR interview, disciplinary discussion or routine control automatically becomes a private investigation.

The right starting point is therefore not to label every internal review as a PIA investigation. It is to understand how investigations actually take place within the organisation and assess whether those activities fall within the scope of the legislation.

The date to have on your radar: 16 December 2026

When the new legislation entered into force, employers were given a two-year transitional period to meet the Article 65 policy requirement. That period ends on 16 December 2026.

There is an important distinction here: this transitional period concerns the Article 65 framework. Other applicable obligations under the PIA already need to be observed today.

Article 65 should also not be treated simply as another policy-writing exercise. Article 101 of the Act lists Article 65 among provisions prescribed under penalty of nullity, meaning the absence of the required framework can create problems where information gathered during an investigation is later relied upon as evidence.

For organisations, the practical message is simple: The moment to think about how you investigate is before you need to investigate.

So, are you ready?

A useful starting point is to look at the organisation from the perspective of a real incident.

Imagine a significant whistleblowing report arrives tomorrow.

Who receives it? Who decides whether an investigation is necessary? Who gathers the facts? Which methods can be used? Which safeguards apply? And where are those rules documented?

If the answers sit across different policies, depend on informal practices or are simply unclear, now is the right moment to review the framework. That review may involve existing whistleblowing, HR, disciplinary, fraud response, compliance, ethics, privacy and investigation procedures, rather than looking at Article 65 in isolation.

The objective should be a framework that is not only legally appropriate, but also workable when the organisation faces a sensitive investigation and decisions need to be taken quickly.

How Grant Thornton can help

Preparing for Article 65 starts with understanding how investigations work in practice within your organisation.

Grant Thornton can support organisations in assessing how the PIA/WPO applies to their activities, reviewing existing investigation arrangements, identifying gaps, and developing or reviewing the required internal investigation framework.

This can include:

• assessing the applicability of the PIA/WPO to existing investigation activities;
• mapping how internal investigations are currently initiated and conducted;
• performing a gap assessment against the relevant PIA/WPO requirements;
• drafting or reviewing an Article 65-compliant investigation policy;
• aligning the framework with existing whistleblowing, HR, fraud, compliance, ethics and privacy arrangements; and
• supporting the implementation and communication of the framework.

With 16 December 2026 approaching, organisations have an opportunity to look beyond simply meeting a deadline and ask a broader question:

If we had to investigate a serious concern tomorrow, would our organisation know exactly what to do, who should do it and under which rules?

If the answer is not yet a confident yes, this is a good moment to start the conversation.

Would you like to assess whether your organisation is ready for Article 65? Our Forensic & Integrity Services and Legal teams can help you review your current framework and determine the appropriate next steps.