Evidence Gathering in Amsterdam — How Lawyers Strengthen Their Case

The difference between knowing something and proving it in court

For lawyers practising before the Amsterdam District Court and the Amsterdam Court of Appeal, a recurring challenge is bridging the gap between what your client knows to be true and what can be proven in proceedings. Dutch procedural law places the burden of proof on the party making the claim (Article 150 Rv). When the opposing party denies the facts or presents a different version of events, you need more than your client’s testimony — you need independently gathered, verifiable evidence.

An evidence gathering investigation by a licensed investigation agency produces exactly that: factual findings, documented in a structured report, that meet the court’s requirements for privately obtained evidence under Article 152 of the Dutch Code of Civil Procedure.

Methods of professional evidence gathering

Evidence gathering is not a single method but a combination of techniques tailored to the specific case. Depending on the nature of the dispute, the investigation may include:

• Surveillance: physical observation to document activities, movements, meetings, and behaviours relevant to the case
• Witness investigation: identifying and interviewing witnesses who can provide first-hand testimony about disputed facts
• Digital investigation: analysis of online activity, communications, and digital traces that corroborate or contradict claims
• Administrative source research: examination of public registers, corporate filings, property records, and financial documentation
• OSINT research: systematic analysis of open sources to build a comprehensive factual picture

Each method is deployed with proportionality in mind — the intrusiveness of the investigation must be justified by the significance of the case and the nature of the evidence sought.

Legal framework and admissibility

All evidence gathering by SAJ Recherche is conducted within the framework of the Wpbr and in compliance with the GDPR (AVG). The investigation adheres to the principles that Dutch courts apply when assessing privately gathered evidence:

• Lawfulness: all methods used must be legally permissible
• Proportionality: the scope of investigation must be proportionate to the interests at stake
• Subsidiarity: less intrusive methods are preferred where they can achieve the same result
• Reliability: findings must be verifiable and reproducible

SAJ Recherche holds a POB licence. The final report is prepared specifically for use in legal proceedings, with clear source references and a chain of custody for all evidence collected.

Practical example from Amsterdam

A lawyer at a firm near the Zuidas was representing a client in a non-compete dispute. The former employee denied working for a competitor. SAJ Recherche conducted a combination of OSINT research and surveillance, documenting the individual entering the competitor’s premises on multiple occasions during working hours. Digital research confirmed the person’s active involvement through LinkedIn updates and industry event registrations. The evidence was submitted in summary proceedings, resulting in a court-ordered injunction and penalty payments.

Facts win cases

In litigation, the quality of your evidence often matters more than the quality of your argument. Professional evidence gathering provides the factual foundation that transforms a plausible claim into a proven case.

Do you need evidence to strengthen your client’s position? Get in touch with SAJ Recherche for a confidential consultation.