London High Court refuses BHP’s appeal bid, cementing liability in the catastrophic 2015 Fundão dam collapse
London’s High Court has refused mining giant BHP’s application for permission to appeal a judgment that it is legally responsible for the collapse of the Fundão tailings dam in Brazil, a disaster that killed 19 people and triggered one of the largest environmental lawsuits in English legal history.
The decision, handed down on 19 January 2026 by Mrs Justice O’Farrell DBE in the Technology and Construction Court, is recorded in the official judgment Município de Mariana v BHP Group (UK) Ltd & Anor.
BHP Group (UK) Ltd and BHP Group Limited were defendants in a group action brought by hundreds of thousands of claimants, including individuals, local municipalities and commercial entities, seeking compensation for losses arising from the collapse of the Fundão dam in Mariana, in Brazil’s Minas Gerais state.
The catastrophic failure of the dam occurred on 5 November 2015. A release of tailings — the waste by-product from iron ore processing — flowed through surrounding communities, destroyed homes, displaced thousands of residents and polluted the Doce River, carrying toxic sludge for hundreds of kilometres before reaching the Atlantic Ocean.
In November 2025, after a lengthy trial on the first stage of the claim, the High Court found that BHP should not have continued to raise the height of the Fundão dam without adequate safety measures, and that this course of conduct contributed to its collapse.
BHP’s subsequent request for permission to appeal that liability ruling was denied by the High Court on the basis that it did not meet the legal threshold for an appeal, meaning there was no real prospect of success and no compelling reason for overturning the original judgment. The court’s ruling is reflected in the official judgment delivered by Mrs Justice O’Farrell.
Under English procedure, a refusal of permission to appeal at first instance does not preclude BHP from seeking leave directly from the Court of Appeal, and the company has said it intends to do so. A spokesperson for BHP said the firm would continue to defend the action and pursue the matter at the appellate level.
BHP also reiterated its position that Brazil remains “the most appropriate avenue to provide full and fair remediation to those impacted”, a reference to ongoing compensation and environmental recovery efforts conducted in Brazil through mechanisms such as the Renova Foundation, established after the disaster.
The group action in London is widely regarded as one of the largest in English legal history. Lawyers for the claimants have valued the potential damages at up to £36 billion, and are also pursuing nearly £200 million in legal costs related to the liability stage of the case.
The initial legal proceedings were brought in the English courts on the basis that BHP Group was at the time of the disaster incorporated in the UK and listed on the London Stock Exchange, a factor that gave the court jurisdiction to hear the claims.
The first stage of the litigation focused on establishing whether BHP was liable to the claimants. The judgment from November 2025 addressed this threshold question and found in favour of the claimants. A second stage trial, scheduled to start in October 2026, will determine the quantum of damages to be awarded, with a ruling expected in mid-2027.
Hundreds of thousands of Brazilians — including individuals, municipalities, businesses and community groups — have joined the action, asserting that the consequences of the Fundão dam collapse extend beyond lives lost to include severe environmental destruction and long-term economic disruption.
BHP’s failure to secure leave to appeal marks a significant development in the case. Legal experts say it reinforces the High Court’s findings on corporate liability in transnational mass tort litigation, and it sends a message about the reach of English courts in holding multinational companies accountable for conduct tied to overseas disasters.