In employment law, it is not uncommon for evidence to have been obtained unlawfully (for example, a theft established through unlawful camera surveillance or unauthorized access to emails). The question then arises whether the court may nevertheless take such evidence into account. The Court of Cassation has provided an important answer to this question through the so-called “Antigoon” case law.
At the time of writing this article, the Act governing private investigations applies within employment relationships. The question arises, however, as to how the so-called “Antigoon” doctrine should be applied within the framework of this Act. According to the Court of Cassation, evidence obtained unlawfully in employment law may only be disregarded in two strictly defined situations, in addition to cases where rules are violated that are expressly prescribed under penalty of nullity (Antigoon case law): namely when the irregularity affects the reliability of the evidence or when its use is contrary to the right to a fair trial.
In several recent cases, the Court of Cassation has overruled other courts that had excluded evidence solely on account of its unlawful nature, without carrying out a concrete assessment against the above criteria. In cases relating to investigations conducted by bailiffs or private investigators (such as searching professional mailboxes or observing employees), the Court has recalled that the mere unlawfulness of the gathering of evidence is not, in itself, sufficient to exclude it.
It is for the judge to assess in concreto whether such unlawfulness - where it is not expressly sanctioned by nullity - affects the reliability of the evidence or infringes the right to a fair trial.
How should this case law be applied to the Act on private investigations?
The Act on private investigations provides that certain provisions are sanctioned by nullity, which consequently justifies the exclusion from the proceedings of documents obtained in breach of those provisions. However, not every infringement of the Act necessarily results in nullity.
The preparatory works clarify that where several investigative methods have been used, the elements established through lawful methods may retain their evidential value, even if part of the investigation is based on an unlawful method.
Recent case law also confirms this nuanced approach. The judge has sovereign discretion to assess the evidential value that may be attributed to the findings of a private investigation, in accordance with Article 101, §3 of the Act on private investigations.
In light of this provision, taking into account the now widely accepted application of the “Antigoon” case law in employment law, its application under the former legislation on private detectives, and the fact that only ten provisions of the Act on private investigations are expressly sanctioned by nullity, we consider that the “Antigoon” doctrine fully applies to this Act.
In our view, it is therefore appropriate to assess, on a case-by-case basis, whether the Act on private investigations expressly provides for a nullity sanction for the unlawfully obtained evidence concerned and, where this is not the case, whether the identified irregularity undermines the reliability of the evidence or the right to a fair trial.
Only in these circumstances should unlawfully obtained evidence be excluded from the proceedings by the court.
By Marjolaine Dessard – Senior Associate Claeys & Engels
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