A mammoth trial centred on a dam collapse considered to be one of Brazil’s worst environmental disasters has opened at London’s Rolls building amid international media interest. 

The 12-week hearing, before Mrs Justice O’Farrell, will assess whether international mining giant BHP, which was formerly listed on the London Stock Exchange, was responsible for the 2015 collapse of a tailings dam in Minas Gerais, Brazil. 

The collapse of the Fundão Dam and resulting flood killed 19 people, destroyed villages and polluted the River Doce system, a water source for local communities. The dam was owned and operated by a Brazilian company jointly owned by mining giant Vale and BHP.

BHP, which denies the claims brought in the UK, previously said the case in the English court is unnecessary as it duplicated issues covered by ongoing legal proceedings in Brazil and the work of the Renova Foundation, a non-profit responsible for reparation of the damages caused by the dam collapse.

London claimant firm Pogust Goodhead, which is bringing the group action on behalf of 620,000 Brazilian claimants, has said it is seeking compensation with a ‘high water mark level of £36bn’.

Opening submissions began this morning with Alain Choo Choy KC, for the claimants, explaining the corporate structure of the BHP Group. Opening submissions are expected to last until Thursday. Written opening submissions totalled more than 700 pages, with the claimants producing a 299-page skeleton argument while BHP’s skeleton runs to 308 pages.