BHP denied UK bid to appeal over Brazil dam collapse

BHP cannot appeal against a UK ruling that it is liable for the 2015 collapse of a dam in southeastern Brazil, London's Court of Appeal has ruled in a case potentially worth billions of pounds.

In November, London's High Court ruled BHP was responsible under Brazilian law for the collapse of the Fundao dam in Mariana, southeastern Brazil, which was owned and operated by Samarco, a joint venture between Australia-headquartered BHP and Brazilian company Vale.

BHP's application for permission to appeal was refused on Wednesday, with the Court of Appeal saying there was "ample evidence" to justify the High Court's findings.

Brazil's worst environmental disaster unleashed a wave of toxic sludge that killed 19 people, left thousands homeless, flooded forests and polluted the length of the Doce River.

At the London trial that started in 2024, lawyers representing hundreds of thousands of Brazilians and other claimants accused BHP, the world's biggest miner by market value, of trying to avoid responsibility.

BHP, however, argued the lawsuit duplicated legal proceedings and reparation and repair programmes in Brazil. In the trial's first week, Brazil signed a 170 billion reais ($A48 billion) compensation deal with BHP, Vale and Samarco.

BHP said it was confident that work done since 2015 and the agreement with Brazil "provide the quickest and most efficient solution" to compensate those affected by the dam failure.

It also said about 240,000 claimants, representing roughly 40 per cent of the claimant class, had received compensation in Brazil meaning their claim will be discontinued.

Pogust Goodhead, the law firm representing the claimants, called Wednesday's decision "a further victory" for the victims and "a major setback" for BHP.

The initial stage of the case was to determine whether BHP was liable to the claimants, with a further trial to decide on any damages to be paid expected to begin in April 2027.