Right to Evidence vs Private Life: The Court of Cassation's Decision of 25 February 2016

Imagine: you are the owner of a property in Maizières-lès-Metz. You rent to a tenant who, after an accident, receives insurance compensation. But you suspect he is exaggerating his injuries to claim more. You hire a private detective. For several weeks, he films him, follows him, questions his neighbours. The result? Overwhelming evidence. But the judge dismisses it. Why? Because the right to evidence does not justify everything. The Court of Cassation, in its judgment of 25 February 2016, set a clear limit: a private investigation, by its duration and scope, may disproportionately infringe upon private life. So, how to reconcile the search for truth with respect for privacy? This decision concerns you, whether you are a landlord, tenant, insurer or ordinary litigant.

The Facts: A Story That Happens Every Day

Mr U., a resident of Sarreguemines, is the victim of an accident. He brings proceedings against his insurer to obtain compensation for his loss. But the insurer doubts the reality of his after-effects. It therefore instructs a private detective to monitor Mr U. for several years. The investigations are extensive: administrative checks, questioning of numerous third parties (neighbours, shopkeepers), surveillance and monitoring near his home and during his travels. Each period of investigation lasts from a few days to nearly two months. The detective produces detailed reports, supposedly proving that Mr U. is not as disabled as he claims.

Before the Court of Appeal, Mr U. requests that these reports be excluded from the proceedings, as they violate his private life. The Court of Appeal refuses: in its view, the infringement is not disproportionate, as the insurer's right to evidence prevails. Mr U. appeals to the Court of Cassation. The Court of Cassation quashes the judgment: it considers that the Court of Appeal failed to draw the consequences from its own findings. Indeed, the duration and scope of the investigations (surveillance, questioning of third parties, monitoring at home) constitute an excessive infringement of private life, even though the insurer sought to prove fraud. The case is remitted to another Court of Appeal.

The Reasoning of the Court — Explained

The Court of Cassation relies on several fundamental texts: Article 8 of the European Convention on Human Rights (right to respect for private life), Article 9 of the Civil Code (protection of private life) and Article 9 of the Code of Civil Procedure (principle of fairness of evidence). It recalls that the right to evidence is not absolute: it must be reconciled with the right to private life. Evidence obtained unfairly or excessively may be excluded.

The reasoning is in two stages: first, the Court checks whether the infringement of private life is indispensable for the exercise of the right to evidence. Then, it checks whether this infringement is proportionate to the aim pursued (here, proving insurance fraud). However, the facts show that the investigation lasted several years, with surveillance and questioning of third parties. Such scope is not proportionate: the insurer could have used less intrusive means (adversarial medical examination, light administrative investigation).

This decision confirms consistent case law: evidence must be fair. It does not establish an unlimited right to investigate. It is a warning for insurers and employers who too readily resort to private detectives. The judge must always weigh the interests at stake: on one side, the search for truth; on the other, the protection of privacy.

What This Means for You — In Practice

If you are a landlord in Maizières-lès-Metz and you suspect a tenant of subletting without permission, you can legitimately seek evidence. But be careful: a surveillance lasting several weeks, with photos and questioning of neighbours, will likely be deemed disproportionate. It is better to favour bailiff's reports or spontaneous testimonies.

For an insurer in Sarreguemines, this decision means that private investigations must be limited in time and methods. Surveillance of a few days, without intrusion into the home, may be acceptable. But not an investigation spread over several months, with records of all movements.

If you are a tenant or victim of an accident, you can challenge evidence obtained through excessive surveillance. Example: you are on sick leave for depression, and your insurer films you doing your shopping. If the surveillance lasts a whole week, you can request that these images be excluded. In such a case, the judge will have to check whether the infringement of your private life is proportionate to the issue (avoiding fraud).

In practice, the cost of such proceedings may vary: expect €1,500 to €3,000 for a challenge before the court, but the chances of success are real if the investigation is excessive. The timeframe? About 6 to 12 months for a first-instance decision.

Four Tips to Avoid This Type of Dispute

• Limit the duration of investigations: surveillance of a few days, on a one-off basis, is more likely to be deemed proportionate than an investigation of several weeks.
• Prefer fair evidence: a bailiff's report, an adversarial medical examination, or testimonies obtained without pressure are less contestable than an intrusive private detective's report.
• Inform the person under surveillance: in some cases, the person's prior consent (if they are informed of the surveillance) may render the evidence admissible. But be careful, this may reduce the element of surprise.
• Consult a lawyer before launching an investigation: a professional will tell you whether your suspicions justify an investigation and in what form. In Maizières-lès-Metz, Maître Zakine can advise you in 30 minutes.

Further Reading: Related Case Law and Developments

This decision is part of a line of protection of private life. For example, in a judgment of 30 April 2009 (No. 08-14.092), the Court of Cassation already excluded video recordings made by an employer in changing rooms, finding the infringement disproportionate. Conversely, in a judgment of 2 February 2011 (No. 09-72.402), it admitted evidence obtained by a private detective who had merely filmed a person in the street for a few minutes, without intrusion.

The trend is clear: judges are increasingly strict on proportionality. With the rise of new technologies (geolocation, drones, hidden cameras), the right to evidence will constantly need to be rebalanced against the right to private life. The 2016 judgment is an essential safeguard.

Summary and Next Steps

FAQ:

• Can I use a private detective to prove that my tenant is subletting? Yes, but the investigation must be limited (a few days, without excessive surveillance). Otherwise, the evidence risks being excluded.
• What if my insurer monitors me excessively? You can ask the judge to exclude the evidence obtained, on the grounds of disproportionate infringement of your private life.
• What is the deadline to challenge evidence obtained illegally? You must do so before the judge rules on the merits. In practice, as soon as you become aware of the investigation, act quickly.
• How much does a procedure to exclude evidence cost? Expect between €1,500 and €5,000 depending on complexity, but a preliminary consultation of €45 can already guide you.
• Does this decision also apply to employers? Yes, the same logic applies in employment law: monitoring of an employee must be proportionate.

Are you in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →