By Sam Tobin

LONDON (Reuters) – BHP is cynically trying to evade its responsibility for Brazil's worst environmental disaster, lawyers representing thousands of victims said at London's High Court on Monday, as a lawsuit worth up to 36 billion pounds (April 47) was filed billion US dollars) began.

More than 600,000 Brazilians, 46 local governments and around 2,000 companies are suing BHP over the 2015 collapse of the Mariana Dam in southeastern Brazil, which was owned and operated by BHP and Vale's Samarco joint venture.

The collapse of the dam unleashed a wave of toxic sludge that killed 19 people, left thousands homeless, flooded forests and polluted the entire Doce River.

BHP, the world's largest miner by market value, denies liability and says the London lawsuit is a duplicate of lawsuits and redress and repair programs in Brazil and should be dismissed.

It also says that almost $8 billion has already been paid out to those affected through the Renova Foundation, with around $1.7 billion going to plaintiffs involved in the English case.

The lawsuit, one of the largest in English legal history, entered the crucial phase on Monday with the start of a 12-week trial to determine whether BHP is liable.

Plaintiffs' lawyer Alain Choo Choy said in court papers released Monday that “a gap exists between what BHP considers 'acceptable' and the compensation that plaintiffs feel they are legally and morally entitled to.”

He argued that BHP's actions in fighting the case and funding a separate lawsuit in Brazil showed the miner was “cynically and persistently trying to evade responsibility.”

“Although this is BHP's decision, the company cannot currently claim to be a company that is 'doing the right thing' by the victims of the disaster,” Choo Choy added.

'EXAGGERATED'

BHP argues that it neither owned nor operated the dam, which contained mining waste known as tailings. It said a Brazilian subsidiary of its Australian holding company was a 50 percent shareholder in Samarco, which operated independently.

The miner also said he had no knowledge before the collapse that the dam's stability was at risk.

Lawyers representing the miner said in court filings: “There is no law or contract that imposes any security obligation on the ultimate parent company of a non-controlling shareholder and the other parent company of the same group of companies.”

“There was also no violation of this safety obligation. And BHP’s actions or inactions did not cause the collapse.”

BHP also said parts of the lawsuit were “uncredible or exaggerated.”

The story continues

Monday's hearing follows developments in BHP's negotiations with Brazilian authorities over the disaster. The Brazilian government is discussing a compensation deal worth almost $30 billion with BHP, Vale and Samarco, it said on Friday.

Tom Goodhead, CEO of Pogust Goodhead, the law firm representing the plaintiffs, told reporters that disaster victims were not involved in the proposed deal.

“People just feel like it’s too little, too late,” he told the Supreme Court. “They want to move forward with the process and hold them accountable.”

BHP said in a statement that it was trying to “complete a fair and comprehensive compensation and rehabilitation process.”

The 12-week hearing will also examine whether Brazilian municipalities are allowed to take legal action, the impact of any agreements with BHP by the plaintiffs involved in the English lawsuit and whether the claims were brought too late.

(Reporting by Sam Tobin, Editing by Mark Potter and Barbara Lewis)