The authorities "estimate the preliminary value for repairs to be 155 billion reals," the public prosecutor's office in the state of Minas Gerais said in a statement.
The announcement sent BHP's share price plummeting 9.36 per cent to close at 18.79 Australian Dollar in Sydney, with a fall in iron ore prices adding to the selling pressure.
Brazilian-owned Vale and Anglo-Australian BHP, which co- own the Samarco iron ore facility, had already agreed to a separate settlement of USD 6.2 billion with the Brazilian government in March.
But the deal was criticised by prosecutors, who said that the amount of money was not calculated realistically.
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The accident on November 5 last year near Mariana in Minas Gerais began when a tailings dam at Samarco's mine failed, unleashing the flood of polluted water and mud into the River Doce, one of the most important in Brazil.
A village was destroyed, drinking water supplies for hundreds of thousands of people were interrupted and damage reached as far as the river's mouth on the Atlantic coast, with wildlife, tourism businesses and fishing communities all suffering.
Paulo Hartung, governor of Espirito Santo state, which also straddles the River Doce, has said the toxic flood marked "the biggest environmental disaster in the history of Brazil."
The civil suit filed yesterday called on Samarco's co-owners to "completely" compensate for the disaster.
Prosecutors said they calculated the USD 43 billion figure based on charges faced by BP after the Deepwater Horizon oil spill in the Gulf of Mexico in 2010.
BHP said in a statement to the market the lawsuit filed yesterday was for "social, environmental and economic compensation."