The Brazilian assets of mining companies BHP Billiton and Vale have been frozen by a judge, ruling that their joint venture Samarco has failed to pay for damage caused by the rupture of a tailings dam at its Germano mining site in November.
Judge Marcelo Aguiar Machado in Brazil's state of Minas Gerais did not specify the value of assets that have been seized.
Reuters quoted the judge saying: "I understand to be correct the allegation that Vale and BHP, as controllers of Samarco, can be classified as indirect polluters and as such responsible for the environmental damage caused."
Following the incident, the Brazilian Government fined Samarco $66m.
Both companies told the news agency that they were not notified about the decision.
The judge ruled that an extensive clean-up plan should be put in place by both companies and Samarco needs to contract a company within ten days to assess contamination caused by the mudslide.
In case BHP and Vale fail to meet the deadlines imposed, they are set to face a daily fine of R$150,000 ($37,524).
In response to the incident, Samarco said in a statement: "Monitoring of the remaining dam structures at Samarco continues.
"Interim work to repair the damage to the dams and to reinforce parts of the structure continues, with work on the Selinha dike (which is the wall between the Germano and Fundão dams) and the Santarém dam being over 50% complete."
BHP Billiton also appointed Flávio Bulcão as Country Director, Brazil to lead the team based in Belo Horizonte and support Samarco in the recovery efforts.
BHP Billiton chief commercial officer Dean Dalla Valle said: "Flávio's appointment forms part of BHP Billiton's commitment to supporting Samarco in rebuilding communities and restoring the environment following the tragedy in Minas Gerais.
"He will lead our in-country presence supporting Samarco and playing a direct role in BHP Billiton's commercial, legal, government and regulatory engagement in Brazil over the long-term."
Seventeen people are reported to have died as a result of the ruptured dam, with thousands of acres of land expected to be contaminated from the mine water.