Companies better not hesitate to implement the PIA in their HR policy

In one of the first cases in which the Act regulating Private Investigation (PIA) applied, the Antwerp Labour Court of Appeal had to examine the results of a private investigation used as evidence in proceedings concerning the recognition of a dismissal for serious cause of a protected employee. Both at first instance and on appeal, the final report was declared null and void. The judgment of 26 December 2025 demonstrates the importance of strict compliance with the PIA.

The Facts

The employee was an employee representative on the works council as well as a member of the trade union delegation. In a digital system, the employee had to manually indicate which commuting he carried out in the performance of these mandates. Based on that information, the employee’s working time and possible mileage allowance were calculated. The employer found that the employee did not always use the system correctly and at times even entered fictitious addresses. The employer repeatedly confronted the employee about this and sent many warnings, without result.

When the employer also discovered that the employee was active in another company without having informed the employer of this secondary activity, a licensed private investigator was engaged to examine the facts and collect evidence.

This licensed private investigation firm conducted a total of 11 observations over three separate periods of one month each. These observations showed that on various days the employee stayed at home at times when he had indicated being present elsewhere in connection with his assignments, and thus committed fraud with the system. The findings were included in a final report.

The decision of the Antwerp Labour Court 

Both at first instance and on appeal, the final report was declared null and void. According to the PIA, the observations must be limited to a duration of less than four consecutive days (ninety‑six hours) or to four non‑consecutive days spread over one month. According to the Labour Court of Appeal, in the case of non‑consecutive observations, the relevant element is not the number of hours but the number of days. As soon as an observation takes place on a given day, even for a short period of time, that day counts in full. The observations were therefore considered too extensive, leading to the nullification of the findings of the private investigation. Consequently, the private investigator’s final report could not be used as evidence of the serious cause.

Unlike the labour tribunal at first instance, the Labour Court of Appeal found that other evidence of fictitious movements was indeed available. The employer was able to demonstrate, based on the registrations made by the employee, that the employee had in fact entered fictitious, non‑existent addresses. Since the employee had no valid explanation for this, the serious  cause was therefore recognised by the Labour Court.

Key message 

This judgment demonstrates the importance of strict compliance with the PIA: observations can be a useful investigative measure in the context of an internal investigation into employees, but must be carried out within the strict legal framework. Although this judgment, as far as the application of the PIA is concerned, related to an investigation conducted by an external private investigation company, it also serves as a warning for HR. The judgment clearly shows that a single misstep can completely undermine and invalidate an otherwise carefully conducted investigation.

We therefore briefly remind you of the key principles of the PIA:

• The scope of the PIA is very broad: it also applies to employers who wish to engage a private investigator or who wish to conduct their own investigation into their employees.
• An employer may only conduct a private investigation into its own employees if the authorisation and modalities for doing so are explicitly and transparently provided for in a “regulation”. This regulation must be in place by 16 December 2026 at the latest.
• It can be argued that anyone involved in an investigation (e.g., in‑house legal counsel, internal auditor, IT, etc.), with the exception of – under certain conditions – the HR department, must be part of a licensed internal investigation service and must possess an identification card.
• Investigative measures may only take place after (1) the required formalities regarding these measures have been completed, and (2) the conditions and modalities laid down in the PIA have been respected (e.g., a person being questioned must give their prior consent and receive specific information).
• The conclusion of an investigation requires the preparation of an investigation report.
• Before the employer can proceed with (disciplinary) measures or dismissal based on the content of the report, information must be provided transparently regarding, among other things, the GDPR rights of the individuals concerned in relation to their personal data (such as the right of access and to obtain a copy, the right to rectification, etc.).

It is important to emphasise that every company must carry out the “PIA exercise”. This ensures that investigations into employees – for example when there are suspicions of fraud, theft, unauthorised or unfair practices – can be conducted correctly and that the results of such investigations can also be used before a court.

We remain at your disposal to support you with the concrete implementation of the PIA within your organization.