In France, and now before the Unified Patent Court (UPC) as well, a saisie is the instrument par excellence needed for when proving infringement. Although highly effective, it is strictly regulated due to its invasive nature and the fact that the procedure for obtaining it is in principle non-adversarial. In France, in addition to an ad hoc legal framework, case law, and particularly the Cour de cassation (French Supreme Court) has, over the years, laid down obligations that the applicant is required to comply with.

In case of failing the obligations, he risks having its authorisation withdrawn or its saisie revoked after several years of proceedings, and thus being deprived of any proof of infringement. These obligations include the duty of loyalty. In a decision issued on 6 December 2023, the Cour de cassation has recalled that, while a rights holder does not have to justify any special circumstances to obtain authorisation to carry out a saisie (it only must show that it has standing to sue and provide prima facie evidence of the infringement), this measure must remain fair, loyal and proportionate. The claimant is therefore required to set out all the objective facts that will enable the judge to exercise its discretion in assessing the circumstances of the case, so that it can reach a proportionate decision.

In this case, Puma had obtained an order authorising a saisie at Carrefour's premises. During the infringement action brought following the conduct of these operations, Carrefour argued that the saisie reports were null and void, pointing out that Puma had not informed the judge of information that would have been useful in reaching its decision. Carrefour argued that the allegedly infringing sign had been the subject of trademark registrations by Carrefour, that Puma had filed oppositions against the registration of these trademarks, and that decisions had already been issued by the French intellectual property (IP) office by the time the application for a saisie was filed. Further, some of these decisions were upheld on appeal in which the oppositions were rejected due to a lack of likelihood of confusion between the signs at issue. The Court, noting that these elements had not been brought to the attention of the judge who had authorised the saisie, and recalled that the judges are not bound by the decisions rendered in opposition proceedings in question. In this case, the judge concluded that Puma had acted unfairly and consequently revoked the saisie reports - this without prejudging the decision that the judge would have rendered if he had been in possession of the information that had been concealed from him.

As this decision was upheld on appeal, it was against this backdrop that the Cour de cassation, to which Puma appealed, ruled, based on Article 3 of Directive 2004/48/EC and Article 10 of the French Civil Code, that by failing to mention these relevant elements, the claimant had breached his duty of loyalty. The Cour de cassation therefore ruled that the Court of Appeal was right to revoke the saisie reports, thereby depriving the claimant of the evidence gathered more than six years earlier.

While the invasive and non-adversarial nature of saisies justifies a particular duty of loyalty on the party requesting such a measure, the scope of this duty may prove difficult to grasp. A party's disloyalty is assessed in the light of the importance of the omitted information, taken in its overall context, which therefore varies from case to case. It is therefore with a degree of caution that the applicant must assess, in the light of all the circumstances of the case, whether the omission of information could be considered disloyal.

Before the Unified Patent Court, Rule 192(3) of the Rules of Procedure also requires the applicant for a preservation order "to disclose any material fact known to it which might influence the Court in deciding whether to make an order without hearing the defendant", in essence repeating the duty of loyalty. This obligation was very recently clarified by the Paris Local Division which, in an order dated 1 March 2024 in C-Kore Systems Limited v Novawell, held that the applicant for a saisie has a duty to make a fair and undistorted presentation of the facts justifying such a measure, particularly – but not only – when it is sought ex parte.