The High Court’s decision in JSC Commercial Bank Privatbank v Kolomoisky [2025] EWHC 1987 has clarified that parties in civil proceedings must disclose any prior judicial criticism of their expert witnesses, even if the criticism arose in unrelated cases. This ruling suggests a broader duty of transparency in civil litigation, aligning more closely with expectations long established in criminal practice. This article outlines the scope of the duty, its practical implications and how firms should respond when instructing experts. What does the duty of expert disclosure require? In Kolomoisky, Mr Justice Trower held that parties must inform the Court of any adverse judicial remarks made about their experts in previous proceedings. This applies regardless of whether the earlier criticism relates to the same subject matter or area of law. Although criminal procedure rules explicitly require such disclosure, civil rules – including CPR Part 35 and the Civil Justice Council’s guidance – do not currently impose a similar obligation. Nevertheless, this judgment makes clear that a duty of candour exists in civil litigation, requiring parties to be open about any information that could affect the reliability or impartiality of expert evidence. Practical implications for law firms and litigators The ruling has immediate consequences for how firms select and instruct experts: Due diligence: Firms must now investigate an expert’s litigation history more thoroughly, including reviewing previous judgments for any adverse commentary Disclosure requirements: If a party is aware of prior criticism, it must be disclosed to the Court, even if the expert was criticised in a different context or jurisdiction Risk management: Failure to disclose may result in reputational damage, reduced weight given to the expert’s evidence, or exclusion of that evidence altogether In Kolomoisky, the expert had been criticised in three earlier cases, but these were not disclosed. The Court found that this omission undermined the expert’s credibility. Fairness and firm responsibilities The judgment raises legitimate concerns about proportionality. Should criticism from years ago potentially in a different legal or technical context affect an expert’s standing today? The Court acknowledged this tension but emphasised the importance of transparency. The duty is not intended to disqualify experts automatically, but to ensure the Court is fully informed when assessing their evidence. To manage this risk, firms should: Ask experts directly whether they are aware of any prior judicial criticism Review publicly available judgments involving the expert Make disclosures proactively, even if the expert believes the criticism was minor or unrelated Keep records of the vetting process and any disclosures made This approach ensures fairness to the expert while maintaining the integrity of the litigation process. What the Kolomoisky decision means for future litigation practice The Kolomoisky decision signals a shift in civil litigation practice, requiring greater openness about an expert’s history in Court. While not codified in CPR Part 35, the judgment sets a persuasive precedent that firms should take seriously. For practitioners, this means more rigorous expert selection and a need to balance longstanding relationships with the duty to disclose. For clients, it offers reassurance that expert evidence is being scrutinised with integrity and transparency. How Morr & Co can help? If you have any questions or would like any further information on the content of this article, please do not hesitate to contact our Dispute Resolution team on 0333 038 9100 or email info@morrlaw.com and a member of our expert team will get back to you. Disclaimer Although correct at the time of publication, the contents of this newsletter/blog are intended for general information purposes only and shall not be deemed to be, or constitute, legal advice. We cannot accept responsibility for any loss as a result of acts or omissions taken in respect of this article. Please contact us for the latest legal position. Authored by Ross Butland Associate Solicitor Message Tags News On this page Contact our team today to find out more get in touch
