On 6 December 2024, a new and far-reaching law was published in the Belgian Official Gazette: the Private Investigation Act. What many business leaders haven't realised yet is that this law is not only important for private investigators or detective agencies. It affects the core of how every company deals with internal investigations, fraud, and personnel files.
Why a new law?
The previous Detective Act dated back more than 30 years. It no longer took into account modern investigative techniques, digital methods, new legal principles regarding privacy, or the current role of private investigation within the global security landscape. The new act provides a completely renewed framework that is adapted to contemporary reality.
The law is based on 5 fundamental pillars:
- Balance between public and private investigation: the law ensures that private investigators cannot go beyond public detectives.
- Profile-neutral legislation: applicable to all types of private investigative activities, regardless of specialisation.
- Protection of privacy and fundamental rights: strict rules and oversight mechanisms.
- Maintaining Quality and Reliability Standards: Training and Vetting Requirements.
- Control and supervision: proactive and reactive government control options.
What is ‘private investigation’? (Art. 3)
The law defines private investigation as an activity that cumulatively meets four conditions:
- Carried out by a natural person;
- On behalf of a commissioning party;
- The collection of intelligence on natural or legal persons;
- With the aim of safeguarding the client's interests in an actual or potential conflict, or to trace missing persons or stolen goods.
Please note: internal investigations by your own HR department or internal fraud department may also fall under this definition.
The articles that directly affect you as a client
Permit requirement (Art. 7 & 8)
No one may offer or organise private investigation services without prior authorisation from the Minister competent for Internal Affairs (IBZ). Nor may you, as a company, use the services of an unauthorised firm.
| ⚠ Are you using a private investigator or detective agency? Verify their IBZ permit. In its absence, all findings are legally void. ⚠ |
Prohibited data (Art. 57 & 58)
It is forbidden to obtain or transmit certain categories of data. These include, but are not limited to:
- Political, religious or philosophical beliefs;
- Genetic or biometric data;
- Sexual behaviour or orientation;
- Health data, crucial for insurance companies and HR departments;
- Undisclosed suspicions or convictions;
- Race or ethnic origin;
- Journalistic information sources;
- Classified information.
Article 58 further connects this: even indirectly derivable information is prohibited, even if the data itself is not explicitly stated.
Investigation into own employees (Art. 65)
This article is particularly relevant for businesses. If the individual is an employee of the client, a private investigation may only be accepted if the authorisation and the further rules are explicitly and transparently laid down in an employment regulation.
| 🚨 DEADLINE: Companies must prepare themselves for 16 December 2026. Start updating your employment regulations today. |
Prohibited methods (Art. 81)
Private investigators are not permitted to perform acts, use methods, or apply coercive measures that are exclusively reserved for the police, intelligence services, or judicial authorities. This prohibition also applies to assignments that you, as a company, might issue.
Prohibition of observation (Art. 87)
Any observation in homes, private spaces, or places where individuals have a reasonable expectation of privacy is prohibited. This also affects the use of GPS trackers, video surveillance in areas with an expectation of privacy, and similar techniques.
Use of unlawfully obtained information (Art. 96)
A private investigator may not use information that he or others have obtained unlawfully. Nor may he incite others to gather such information. You, as the client, also bear responsibility here.
Confidentiality of files (Art. 109)
Data from a research file for client A must never be used in a file for client B. This places strict demands on the information management processes of research firms.
The sanction of nullity: what does this mean in practice?
Article 101 is the linchpin of the entire Act. The judge to whom the findings of a private investigation are submitted will ascertain whether the investigation complies with the provisions of the Act.
The following articles are expressly prescribed on pain of nullity:
| Article | Subject |
| Article 7 | Licence requirement for private investigation |
| Article 8 | Prohibition of the use of unlicensed services |
| Article 57 | Prohibition on the collection of prohibited data categories |
| Article 58 | Prohibition of indirectly derivable prohibited data |
| Article 62 | Prohibition of contracts relating to intelligence and security services |
| Article 65 | Terms and conditions for investigating own employees |
| Article 81 | Prohibition of methods reserved for the police/judiciary |
| Article 87 | Prohibition of observation in private places |
| Article 96 | Prohibition on the use of unlawfully obtained information |
| Article 109 | Prohibition on the reuse of file data |
A penalty for nullity means that if the investigation does not comply with these articles, it will be considered non-existent. The judge will not assign it any evidential value. What's more, the verdict will be forwarded to the minister responsible for Internal Affairs, which may lead to additional sanctions.
Many uncertainties remain, but the nullity is already a fact
The law still leaves considerable room for interpretation. The practical implementation details will be set out in royal decrees which are currently being drafted. Matters such as the precise methods that are permitted, the training requirements, the concrete interpretation of the concept of ‘private investigation’ in specific situations - all of that will be further clarified.
But it's important that every business owner is aware of the following:
| The articles prescribed on pain of nullity (Articles 7, 8, 57, 58, 62, 65, 81, 87, 96 and 109) are in effect. Now. For everyone. Waiting for the Royal Decrees is no excuse. |
What should you do as a company now?
- Check if your external research partners have a valid IBZ permit.
- Review your internal regulations and add a transparent procedure for internal investigations. Be ready by 16 December 2026.
- Evaluate your current internal research procedures for conformity with prohibited methods and data categories.
- Ensure your HR and legal teams are aware of the new obligations.
- Ask a recognised private investigation firm for advice to test your compliance.
Do you have any questions about the impact of this law on your organisation?
Contact our office. We will help you align your working methods with the new law: proactive, pragmatic, and with expertise.