Private detective for individuals in Paris

A private detective for individuals legally gathers the evidence that makes the difference before a judge: adultery, child custody conditions, hidden income, locating a relative or a debtor, unauthorised subletting. CNAPS-licensed, we operate in Paris and the Île-de-France region in strict compliance with privacy law.

Written by Guillaume Pouillier, CNAPS-licensed private detective, licence no. AGD 095-2024-03-06-20190240581 · Last updated: July 19, 2026

What investigations do we carry out for individuals?

Most of our casework involves family and asset matters: proving adultery before a divorce, documenting child custody conditions, revealing hidden income for alimony purposes, locating a person, proving unauthorised subletting or a breach of trust. Every assignment starts with a free consultation that verifies your legitimate interest.

Before a major commitment, consider a premarital investigation; and at divorce time, a compensatory allowance investigation, the other party’s real standard of living directly affects what the judge awards.

Is evidence of adultery or lifestyle admissible in French courts?

Yes. Since the Court of Cassation ruling of 7 November 1962, a private detective’s report has been accepted as evidence, including before the family court judge, provided the material is obtained fairly, without intruding into private premises, and proportionately to the aim pursued.

In practice, we work from public space and open sources: observations and photographs on the public highway, recorded comings and goings, schedules, vehicles, visible online activity. In divorce matters, article 259 of the French Civil Code admits proof by any means, subject to the classic fairness requirement. Our licence (art. L621-1 of the Internal Security Code) and professional secrecy (art. 226-13 of the Criminal Code) frame the whole process.

How much does a private detective cost for an individual?

Our rates are public: €85 (excl. VAT) per hour, a 4-hour package at €340, a full day (10 h) at €850, volume discounts, and administrative investigations from €350. The written quote is free, follows the confidential consultation, and nothing is exceeded without your agreement.

Most family cases are handled through targeted sessions: a few well-chosen time slots (home departures, weekends, recurring journeys) are often enough to establish the facts. An alimony or inheritance case is more documentary and spreads over more weeks but uses fewer field hours. The full grid is on our rates page.

Before comparing prices, weigh the cost of the investigation against what you stand to lose: a fair compensatory allowance, a revised alimony, your children’s custody or the family estate.

How does your investigation unfold, in complete discretion?

Four stages: a free confidential consultation to qualify your situation and verify the legitimate interest; a written engagement letter setting the object, duration and budget; the field investigation conducted by licensed investigators; a detailed, dated and signed report, delivered in person or through a secure channel.

1. Confidential consultation. You explain your situation; we tell you what can be established, in what timeframe, at what cost, and whether an investigation is needed at all.

2. Written engagement. Precise object, legitimate interest, scope, budget: the contract that secures the admissibility of the evidence.

3. Investigation. Observations in public space, open sources, dated findings, with a progress point as soon as significant results emerge.

4. Report. Chronology, findings, time-stamped photographs: the document your lawyer files as is before the judge.

Your spouse, your circle or your tenant are never alerted: discretion is a professional obligation as much as a condition of effectiveness. Our methods are set out transparently.

After delivery, the report remains yours: many clients hand it to their lawyer to open proceedings, others use it simply to make an informed decision. Either way, we remain available to your counsel to explain how each finding was obtained, a point that matters if the other side challenges the evidence.

Why entrust your case to Prometheus in Paris?

A CNAPS-licensed agency at 10 rue de la Paix (Paris 2nd), backed by the Prometheus Group’s 30 years of experience, more than 550 investigations a year, a network of investigators covering Paris and Île-de-France, and one constant requirement: only produce evidence a judge can use.

Family matters demand a dual skill set: legal rigour, knowing what a family court judge will retain, and human tact, because behind every assignment there is a couple, children, an estate. Our investigators are trained in both. You are received by appointment at the agency, steps from Place Vendôme, or by phone and video call; everything is covered by professional secrecy, including towards your relatives.

We operate throughout Paris, notably the 8th and 16th arrondissements, and across Île-de-France, from Hauts-de-Seine to Val-de-Marne.

We regularly assist English-speaking clients and expatriates living in Paris, as well as foreign lawyers whose cases have a French connection. Consultations can be held in English; the investigation report is drafted in French, as required for use before French courts, and we walk you through its contents so nothing is lost in translation.

✓ CNAPS licensed · Professional secrecy (art. 226-13) · Free consultation, 7 days a week

Frequently asked questions