BHP before the High Court over the 2015 Mariana Dam collapse

A hearing to examine BHP’s role and possible responsibility for one of the worst environmental disasters ever to occur in Brazil begins today at the High Court in London.

BHP could face up to £36 billion in damages from a class action, which law firm Pogust Goodhead is bringing on behalf of more than 600,000 claimants.

The lawsuit is the largest of its kind in English legal history and also includes 46 local governments, around 1,500 businesses and dozens of religious institutions as plaintiffs.

In November 2015, the Mariana Dam in Brazil’s Minais Gerais region failed, releasing millions of cubic meters of toxic waste, known as tailings, from a local iron ore mine.

Nineteen people died, the waterways of a local river were poisoned, and the town of Bento Rodrigues was destroyed by the dam collapse.

BHP, the world’s largest listed miner, had a 50 percent stake in the mine under a joint venture called Samarco with Brazilian multinational corporation Vale.

Four years ago, the company successfully brought a case against the class action, with a High Court judge calling it an “abuse of process,” but this decision was overturned two years later by the Court of Appeal.

It has already paid almost $8 billion in compensation since 2016 and is negotiating additional payments of $23.8 billion to compensate authorities and communities directly affected by the disaster.

Pogust said the proposed deal represented a “desperate attempt by BHP to avoid being held to account”.

The firm added: “The individual compensation amounts offered in the proposed settlement are wholly unsatisfactory, reflecting a lack of victim involvement in the negotiations and completely ignoring individual circumstances.”

Pogust is bringing the case against BHP in London because the mining giant had a dual listing structure, based in the UK and Australia, at the time of the disaster.

It maintains that BHP is liable because of its involvement in Samarco and the financial benefit it derived from the project.

However, BHP claims it had no day-to-day role in the operations of the mine and dam and that councils cannot bring claims in London. The case will last up to 12 weeks.

In a statement to investors, BHP said it “will continue to defend the action which it considers unnecessary because it duplicates issues already covered by ongoing remedial work and legal proceedings in Brazil.”

BHP Group Shares They rose 0.5 per cent to £21.97 on Monday morning, but have fallen around 19 per cent since the start of the year.