Global mining giant BHP wants joint venture partner Vale S.A. to contribute towards damages if it is found liable in a multi-billion-pound lawsuit over a dam collapse that led to Brazil’s worst environment disaster.

The first-stage trial over the dam collapse is due to be heard next year. There are more than 720,000 claimants.

The Fundão dam, in Minas Gerais, Brazil, collapsed in 2015. The disaster killed 19 people, destroyed villages and released millions of cubic metres of toxic waste, some of which swept into the River Doce, a main water supply, and reached the Atlantic, more than 400 miles away.

Claimants in the group action are seeking compensation over the collapse of the dam, which was owned and operated by Samarco Mineração, a joint venture between BHP and Brazilian iron ore mining company Vale. BHP’s liabilities in the class action were estimated at £5bn in 2018.

BHP denies any liability. The multinational company and Vale appeared in the Rolls Building this week for a two-day hearing on jurisdiction and liability applications.

BHP claims Vale should share the burden of any liability found and contribute 50% or more towards any payments made. Vale argues England and Wales is not the correct jurisdiction to hear the claim.

Shaheed Fatima KC told the court: ‘There is no reason why co-debtor one can’t…ask for declaration of the application of that liability. What we are asking the court [to do is] declare Vale's [portion of] liability is 50% or more. If payment is made to the claimants by BHP, [there] would be support order requiring Vale to make payment to BHP, after BHP had paid the claimants.

‘If BHP are liable to claimants then Vale is also liable. It is uncontroversial as a matter of law.’

In court filings, Vale, a third party/Part 20 defendant, said a claim for declaratory relief ‘is premature, where for example, the claimant will have no claim against the defendant for a number of years. It is hypothetical where, as here, the claim may never arise at all’.

Vale, which also brings jurisdiction applications as it argues ‘Brazil is plainly the jurisdiction’, said in court documents it has no present liability to BHP and the court should not grant relief ‘as to any hypothetical future liability’.

The hearing follows a judgment of Mrs Justice O’Farrell in which she determined the first stage trial would begin in October 2024 with an estimate of 11 weeks.

Judgment was reserved.