A law firm representing more than 200,000 Brazilian citizens has filed a $5-billion claim again BHP Billition for damages caused by a dam collapse in 2015.

The law firm, SPG, said in the suit that BHP Billiton "knew of the risks" at the Samarco Mine in Minas Gerais state. The tailings dam at the site collapsed, killing 19 people and displaced more than 700 in what is regarded as the worst environmental disaster in the country’s history.
The claim, which was served at Liverpool's High Court, is the largest in United Kingdom legal history, the BBC reported.

BHP, an Anglo-Australian firm listed in London, rejects all of the charges.

Tom Goodhead, partner at SPG, said: “The repeated warnings and recommendations of dam safety experts were acted upon too slowly, or sidestepped entirely.

“Driven by concern for declining revenues amidst the falling market price of iron ore, the company took risks, increased production and turned a blind eye to dangers that ultimately claimed lives and destroyed communities.”

The Samarco disaster in Minas Gerais state happened in south-eastern Brazil. When the dam burst, it unleashed a deluge of thick, red toxic mud that wiped out the village of Bento Rodrigues.

It also polluted the Rio Doce river and Atlantic Ocean 650 km away, devastating wildlife and tainting drinking water for hundreds of thousands of people.

The lawsuit is being brought on behalf of 235,000 Brazilian people and organizations, including municipal governments, indigenous tribes, utility companies and the Catholic Church.

It claims BHP failed to act on repeated warnings from independent experts about the dam's integrity. Instead, it claims the miner continued to increase output of iron ore, leading to heightened water levels.

Goodhead said: "BHP was woefully negligent in its duty of care and the damages sought are entirely commensurate with the devastation the company has wrought upon the people of Minas Gerais, [the state of] Espirito Santo and Brazil."

BHP has rejected all charges against the company, as well as current and former staff.

BHP spokesman Neil Burrows said the miner intended to defend itself against the claim. 

The firm has separately settled a class action by U.S. investors over the disaster and continues to battle Australian shareholder lawsuits,
It has also paid millions of dollars into compensation and remediation programs.