London | BHP is “cynically and doggedly” shirking responsibility for the Samarco dam disaster in Brazil, and has built “a wall of omerta” around past and present executives who could shed light on what happened, according to allegations aired in a London courtroom on Monday.

The allegations came in the claim filed by law firm Pogust Goodhead on behalf of its 620,000 Brazilian clients, who are seeking £36 billion ($70 billion) in reparations from BHP – one of the biggest class actions in English history.