Brazilian Federal Public Prosecution Service has filed a R$155bn ($43bn) civil lawsuit against mining company Samarco and its owners Vale and BHP Billiton over the tailings dam disaster in November 2015.
Rupture of the Fundão tailings dam occurred at the Samarco iron ore operation in Minas Gerais in Brazil, killing at least 17 people and releasing an avalanche of sludge that polluted more than 400 miles of rivers.
BHP Billiton said that it did not receive any formal notice of the claim and remains committed to helping Samarco to restore the environment affected by the burst dam.
The 359-page lawsuit demanded that Samarco make an initial deposit of R$7.7bn ($2.18bn) to an independent fund worth R$4.4bn ($1.12bn), which will be used for cleaning up the aftermath.
On 2 March, Samarco, Vale and BHP Billiton Brasil signed an agreement with the Federal Attorney General of Brazil, the states of Espirito Santo and Minas Gerais for restoration of the environment and communities affected.
The agreement was also signed with certain other public authorities and provides a long-term compensation framework for responding to the disaster's impact.
Under the agreement, an Inter-Federative Committee (IFC) comprising 12 government representatives at federal, state and municipal level has been established.
The committee is responsible for validating programme designs, and review progress and achievement of objectives of the remediation programmes.
BHP Billiton said in a statement: "We believe that the agreement (once approved by the court) provides the long-term remedial and compensation framework for responding to the impact of the Samarco tragedy and the appropriate platform for the parties to work together."