English High Court Finds BHP Liable in Landmark £36 Billion Fundão Dam Litigation

On November 14, 2025, the English High Court delivered its judgment on liability in Município De Mariana v BHP Group (UK) Limited & BHP Group Limited [2025] EWHC 3001, finding BHP Group (UK) Limited and BHP Group Limited (together, BHP) liable in a claim valued at approximately £36 billion arising from the 2015 collapse of the Fundão Dam in Brazil.

The Court held BHP, as the ultimate parent company of the dam operator, strictly liable as a “polluter” under Brazilian Environmental Law and liable based on fault (negligence) under the Brazilian Civil Code.

It is the first case where a UK-domiciled parent company has been found liable for the actions of an overseas subsidiary or joint venture and provides an instructive warning that traditional corporate group structures and joint venture arrangements are not guaranteed to insulate parent companies from liability arising from the actions of their subsidiaries.

The judgment on liability proceeds from the Court of Appeal’s judgment at an earlier stage in the proceedings that the claim was not an abuse of process and it was appropriate for the case to be heard in the English Courts. Although the High Court found BHP liable as a matter of Brazilian law, the case forms part of a wider trend where the English Courts have allowed negligence claims against parent companies for the actions of their overseas subsidiaries to proceed in this jurisdiction (see our previous Sidley Update on the UK Supreme Court’s judgment in Okpabi v Royal Dutch Shell plc [2021] UKSC 3).

Background

On November 5, 2015, the Fundão Dam at Samarco’s Germano-Alegria mining complex in Brazil collapsed, causing a number of deaths and widespread environmental and socio-economic damage. The dam was owned and operated by Samarco Mineração S.A. (Samarco), a Brazilian company jointly owned by BHP Brasil and another mining company, Vale S.A.

The claimants issued proceedings in England under the Brazilian Environmental Law, the Brazilian Civil Code, and Brazilian Corporate Law in November 2018 against BHP Group Limited (Australia) as the parent company of BHP Brasil, and BHP Group (UK) Limited, which operated with BHP Australia as a single economic entity.

The case currently involves over 600,000 Brazilian claimants, including individuals, businesses, faith-based institutions, municipalities, utility companies, and indigenous communities.

Jurisdiction and Strike-Out Challenge

In 2019, BHP applied to strike out the claim as an abuse of process and argued that in any event, Brazil was the appropriate forum. In 2020, the High Court struck out the “irredeemably unmanageable” claims as an abuse of process.

In 2022, the Court of Appeal overturned this decision, finding that (i) unmanageability was not grounds for abuse of process and (ii) it was too early to conclude that litigation would be “irredeemably unmanageable” (i.e., before any case management had taken place). The Supreme Court refused BHP’s permission to appeal, clearing the way for the liability trial.

Liability Trial

Strict liability

The Court held that BHP is strictly liable as a “polluter” under Article 3(IV) and Article 14(1) of Brazil’s Environmental Law (and, in the alternative, under Article 927 of the Civil Code). The Court found on the evidence that BHP (together with Vale) was “directly and/or indirectly responsible for the activity of Samarco” in owning and operating the Fundão Dam and undertaking the activity that caused the collapse. Although BHP was not the direct legal owner of the dam, its control, involvement, and assumption of responsibility for Samarco’s operations brought it within the statutory definition of “polluter.”

Fault-based liability

The Court also found BHP liable based on fault under Articles 186 and 927 of the Civil Code. BHP’s control of Samarco, its assumption of responsibility for risk assessment and dam safety, and its active participation in operations gave rise to a legal duty to avoid harm caused by negligent, imprudent, or unskillful conduct. BHP breached this duty in failing to implement recommended remedial measures and causing Samarco to continue raising the dam. According to the judge’s findings, these failures caused the collapse.

Comment

The judgment is a warning to large UK-domiciled multinational companies with complex and sophisticated overseas operations. It follows the judgments in Lungowe v Vedanta Resources plc [2019] UKSC 20 and Okpabi, which illustrated the risk that UK-domiciled parent companies face from mass tort claims in negligence for damages caused by the actions of foreign subsidiaries.

Although BHP was found liable as a matter of Brazilian law, the broader implication is that companies exercising material influence or control over foreign subsidiaries, or joint ventures, face the risk of liability in England, either as a matter of the law of the country in which their subsidiaries operate or as a matter of English negligence law. The claimants sued BHP under Brazilian law given the availability of Brazilian statutes that could give rise to liability of the parent companies. By contrast, in Vedanta and Okpabi, the causes of action available to the claimants were limited to establishing that the parent companies owed an English law duty of care to the claimants for the actions of their subsidiaries.

BHP, Samarco, and Vale had achieved a significant settlement with Brazilian public authorities in relation to compensation for socio-environmental and collective public socio-economic damages, the value of which was approximately £20 billion (the settlements were reached with different entities that had been subject to different proceedings in Brazil and therefore did not preclude the claims in the English Courts against BHP but may reduce the quantum of damages). This, and the fact that the claim has been brought by approximately 600,000 claimants, demonstrates that the English Courts are willing and able to manage large and administratively complex claims (including where the applicable law is that of a foreign jurisdiction) and that significant settlements in the place where damage has occurred will not necessarily prevent claims against parent companies in England.

BHP has announced that it intends to appeal the High Court’s decision. However, the case is already being managed toward the second-stage trial on quantum, which is scheduled for October 2026 to March 2027. Any potential third-stage trial to determine the entitlement of individual claimants to damages is likely to be in 2028 or 2029.