Joris DeeneAnyone who obtains a seizure order regarding counterfeit goods based on a patent that is subsequently found to be invalid is not automatically required to compensate the party subject to the seizure for damages: the party subject to the seizure must prove that a mistake was made. But in this case, that mistake was glaringly obvious. On February 24, 2026, the Brussels Court of Appeal ordered patent holder VR-Drilling and its director to pay over 10,000 EUR in damages, because they had failed to disclose in their unilateral petition that the European Patent Office had already found the invention to be unpatentable. The ruling demonstrates how seriously the duty to disclose information is taken when a party unilaterally brings a case before the court.
The facts
VR-Drilling Equipments develops and sells ground drilling equipment. On July 31, 2017, its director obtained a Belgian patent (BE 1023814) for a drilling rig with a flexible hose having two concentric passages, through which water is simultaneously conveyed at very high and very low pressures. The application was filed on January 28, 2016.
The patent specification contained a notable section: the novelty search conducted by the European Patent Office (EPO). In it, the examiner concluded that the claimed invention was neither new nor inventive, because all of its features were already disclosed in a U.S. patent application dated May 1, 1990 (US 4,921,057). Nevertheless, a Belgian patent is granted without a substantive preliminary examination, so the patent was granted anyway.
Van Moer Marc.com (VMM), a family-owned business specializing in well dewatering and well drilling, had been a customer of VR-Drilling for many years. When VR-Drilling was unable to supply a suitable machine, VMM assembled one itself. VR-Drilling viewed this as counterfeiting and, on January 24, 2018, obtained authorization for a seizure order regarding counterfeiting: An expert was tasked with describing the machine, and the machine itself was sealed. The unilateral petition made no mention of the negative EOB report.
VMM filed a third-party appeal and prevailed on March 22, 2018: the decision was overturned, which the Ghent Court of Appeals confirmed on June 18, 2018. Moreover, the day before the oral arguments on the third-party opposition, VR-Drilling had also filed a criminal complaint, bringing a civil action against VMM and its directors. That complaint was dismissed on February 27, 2019. VMM subsequently sued VR-Drilling and its director in the Dutch-language Commercial Court in Brussels, which declared the patent invalid on June 27, 2019. Two months later, on August 27, 2019, the patent holder partially waived his patent and limited the claims. The case was reheard on appeal.
The ruling
The Brussels Court of Appeals dismissed the appeal as unfounded, addressing five distinct issues in the process.
The Competitor’s Legitimate Interest in the Action for Nullity
VR-Drilling argued that VMM had no legitimate interest in its invalidity action: anyone who engages in counterfeiting themselves should not be allowed to challenge the patent. The Court of Appeals did not follow that line of reasoning. In patent cases, the status of a competitor is sufficient to demonstrate the required interest in bringing an action for invalidation against another company’s patent. That interest certainly exists when the patent holder invokes the patent against that very competitor, as in this case. The fact that VR-Drilling itself accused VMM of infringement did not render VMM’s interest illegitimate; rather, it confirmed it.
No investigative measures and no use of the destroyed expert report
VR-Drilling asked the Court of Appeals to order VMM to submit the plans for its machine and to introduce the expert’s descriptive report from the seized documents into the proceedings, pursuant to Article 877 of the Judicial Code (Ger.W.) The Court of Appeals rejected both.
The reason is a matter of principle. A claim of invalidity is assessed based on the state of the art: everything that was publicly available prior to the filing date of the patent application. The design of the alleged infringer’s machine is irrelevant in this regard. A comparison of the two machines is only relevant to the question of infringement, and that issue was no longer at issue.
Furthermore, the expert’s report had become unusable. According to the court of appeals, the definitive revocation of the decision upon unilateral request extends to everything that was done in implementation of that decision and to everything that resulted from it. The decision is deemed never to have existed, and the official report of the inspection and the expert’s report share that fate.
The invalidity of the patent, even after partial surrender
Pursuant to Article XI.57 of the Code of Economic Law (WER) The court declares a patent invalid if the invention lacks novelty or an inventive step (Articles XI.6 and XI.7 WER). The Court of Appeals first upheld the invalidity of the patent as granted: all features of the independent claim were already disclosed in the 1990 U.S. application, including the hydraulic drive system relied upon by VR-Drilling.
What remained was the limited patent following the partial surrender of August 27, 2019, in which the patent holder highlighted a two-part hose guide as a distinguishing feature. The Court of Appeals applied the problem-solution approach, taking the closest prior art as its starting point and asking, as the ultimate question, whether a person skilled in the art would find the solution obvious. According to the Court of Appeals, a person skilled in the art—in this case, a mechanical engineer—would naturally arrive at a guide divided into two sections: the U.S. patent application already explains that an unrolled hose must be straightened; a division of the guide had already been depicted in a 1996 patent application and applied in a tracked vehicle publicly presented in 2013. The limited patent was therefore also rejected, due to a lack of inventive step.
Compensation for damages resulting from the wrongful seizure in connection with counterfeiting
Now for the key question: Must the party who filed the attachment pay now that his patent has been invalidated and his attachment order has been set aside? The Court of Appeals first outlined the legal framework. Article 1369bis/3, § 2 of the Judicial Code allows the court to order the petitioner to pay appropriate compensation if the measures are revoked or if no infringement is subsequently found. According to the Court of Appeals, this provision does not establish strict liability: strict liability could deter patent holders from using the attachment, which runs counter to the objective of the Enforcement Directive. The liability for negligence under Article 1382 of the old civil code According to the Court of Appeals, (the former Civil Code) strikes a sufficient balance between the debtor and the creditor.
That error occurred here. To compensate for the one-sided nature of the proceedings, the petitioner is subject to a special duty to provide information: the presiding judge must be able to rely on being informed fully and accurately. In its petition, VR-Drilling omitted to mention the EPO report that deemed the invention unpatentable, and subsequently carried out the measures obtained on the basis of that incomplete information. According to the Court of Appeal, by doing so, it did not act as a normally prudent and reasonable petitioner.
The damages were estimated strictly but specifically. It was not proven that VMM’s directors lost a day working on the description itself; that claim for 2,000 EUR was dismissed. What was proven, however, was that VMM had to do without its sealed machine from February 8 to March 22, 2018, and therefore deployed 157 additional staff hours at the job sites. At an average hourly wage of 39.8 EUR, this amounted to 6,248.60 EUR. The additional travel costs and the reduced capacity for other clients, however, were rejected because VMM failed to provide supporting evidence for them.
The Abuse of Procedural Law and the Patent Attorney's Fees
The Court of Appeals identified a second error in the criminal complaint. VR-Drilling did not file that complaint until the day before the arguments regarding the third-party objection, and immediately sought a stay of those proceedings on the grounds that criminal proceedings stay civil proceedings. According to the Court of Appeals, the complaint served solely to delay the proceedings and preserve the attachment, which constitutes an abuse of procedural law. VMM’s damages—two interrogations of its directors and a year and a half of uncertainty—were equitably assessed at 1,000 EUR.
VR-Drilling was also required to pay the 3,500 EUR invoice that VMM paid to its patent attorney for the validity examination. According to the Court of Cassation, costs for technical assistance are not included in the litigation costs that the losing party is ordered to pay (Supreme Court, September 22, 2023, C.22.0287.F), but the court of appeals awarded them as damages pursuant to Article 1382 of the former Civil Code: those costs, too, resulted from the breach of the duty of care. Finally, the Court of Appeals awarded the maximum litigation reimbursement—12,000 EUR at first instance and 15,697.67 EUR on appeal—because the nature of a patent dispute involving a claim for invalidity justifies this amount.
Legal analysis and interpretation
The duty to disclose information was decisive in this case, not the nullity
It is interesting to note exactly what the basis of the judgment was. It was not the fact that the patent was declared invalid: according to established case law, that alone is not sufficient to establish liability. Rather, it was the fact that the negative EPO report was missing from the petition. That report was, however, included with the patent specification; the presiding judge could have read it if someone had pointed it out to him. It was precisely that omission that turned a defensible procedural choice into an error costing 6,248.60 EUR plus 3,500 EUR in expert fees.
The ruling is thus consistent with established case law. In the Snowfall ruling of February 28, 2018, the Brussels Court of Appeals had already found that failing to inform the presiding judge that the right invoked could reasonably be challenged constituted an error. We previously analyzed the same penalty in a case in which a pharmaceutical company concealed that the shipments in question were intended for clinical trials: there, too, the breach of the duty to disclose information until the attachment is lifted. The lesson is always the same: in proceedings without an opposing party, the petitioner must take on the role of the opposing party in the adversarial debate. Anyone who presents only the favorable part of the case file will pay the price for it later.
Fault-based liability or strict liability: the debate is not yet over in Europe
The Court of Appeals expressly opted for fault-based liability and rejected strict liability, arguing that a risk-based regime would deter patent holders. That decision is consistent with the Court of Justice’s Bayer Pharma judgment (Court of Justice of the European Union, September 12, 2019, C-688/17): The mere revocation of the measures or their subsequent annulment does not automatically require the court to issue a judgment against the defendant; rather, the court must weigh all the circumstances.
However, the Court of Justice has since reopened that door. In the Mylan ruling (Court of Justice of the European Union, January 11, 2024, (Case C-473/22), the Court of Justice accepted the Finnish system, which does provide for strict liability: Member States may choose between fault-based liability and strict liability, as long as the court can take the circumstances of the case into account. For Belgium, this means that the legislature could introduce a stricter regime, but that case law does not require it to do so. In this ruling, the Court of Appeal thus adhered to the Belgian position, and the Court of Cassation confirmed in a related patent case that a contrary decision on the merits has no retroactive effect on the earlier decision in summary proceedings (Supreme Court, September 11, 2025, C.23.0110.N). The burden of proof therefore remains heavy for the party against whom the attachment is sought: he must demonstrate a specific error. This ruling immediately points to an important avenue for doing so: a breach of the duty to disclose information.
The expert fees end up being paid by the losing party anyway, albeit indirectly
There is a subtle but practically significant point in the ruling ordering the patent attorney to pay 3,500 EUR. In 2023, the Court of Cassation ruled that the costs of technical advice are not litigation costs: they are not covered by the litigation reimbursement and cannot be recovered as costs. That might seem like an obstacle, but the Court of Appeals easily overcame it: as soon as the opposing party made a mistake, those same expert fees constitute damages within the meaning of Article 1382 of the old Civil Code. The basis shifts from procedural law to tort law, and the outcome is reversed. For the party against whom a wrongful attachment is sought, this makes a tangible difference: their technical defense costs are not lost, provided they prove the attaching party’s error and substantiate payment of the invoice—which VMM did here by providing proof of payment.
Specifically, what does this mean?
For patent holders considering a seizure related to counterfeiting. Present everything to the chairperson, including evidence against you. A negative novelty search by the EPO, an ongoing opposition, a previous rejection, or relevant correspondence: mention it in the petition and explain why you nevertheless believe your right is valid. Concealing information comes at a double cost: first, the revocation of the attachment, and then damages. The same diligence applies to a second attempt: New evidence is admissible only if it was not reasonably accessible before. Anyone who invokes a Belgian patent without a prior art search would be well advised to have its validity thoroughly reviewed in advance and to seek assistance from a lawyer specializing in patent law.
For businesses that are subject to a seizure. Read the attachment creditor’s petition carefully: does it include everything the presiding judge should have known? A concealed negative investigation report is your strongest weapon—first for the third-party objection and then for the claim for damages. Document your damages from day one: the ruling shows that only specifically substantiated items are compensated. The 157 recorded overtime hours earned VMM 6,248.60 EUR; the unsubstantiated travel expenses yielded nothing. And keep both the invoice and the proof of payment from your patent attorney: those costs are recoverable as damages.
For parties to the proceedings in general. Filing a criminal complaint to have civil proceedings suspended is a risky move. The Court of Appeals interpreted the timing—just days before the oral arguments—as having a purely delaying purpose and ruled that it constituted an abuse of procedural rights. The timing of your procedural actions is also taken into account.
Frequently asked questions (FAQ)
Is the infringer always required to pay damages if his patent is declared invalid?
No. The invalidation of the patent or the lifting of the attachment is not sufficient in and of itself. The party subject to the attachment must prove that the party who initiated the attachment acted in error—for example, that the latter withheld relevant information from the presiding judge or knew that his right was invalid.
What must be included in a unilateral petition for attachment regarding counterfeit goods?
All relevant information, including adverse information: a negative prior art search, previous or pending proceedings concerning the same right, and relevant correspondence. The chairperson decides without the opposing party present and must therefore be able to rely on the completeness of the petition.
Can the expert report from a vacated attachment proceeding regarding counterfeiting still be used?
No. The revocation of the decision means that it is deemed never to have existed. Anything done in accordance with it—including the official report of the inspection and the expert report—may no longer be submitted or used.
Conclusion
The February 24, 2026, ruling by the Brussels Court of Appeals reaffirms the Belgian position: anyone in Belgium who issues a seizure order for counterfeit goods based on a right that is later found to be void is not automatically liable; however, anyone who provides incomplete information to the presiding judge commits a fault and is liable for the full costs. For VR-Drilling, this amounted to over 10,700 EUR in damages and nearly 28,000 EUR in litigation costs. The duty to provide information in a unilateral petition is not a mere formality, but the very essence of Belgian procedural law in the area of intellectual property rights.
Dutch 
English