BHP and Vale reached a $US2.4 billion settlement with Brazilian authorities in March over the November 2015 Samarco tailings dam collapse which killed 17 and left hundreds homeless.

The deal suspended the public claim, which sought the establishment of a 20 billion real compensation and clean-up fund.

The settlement agreement was ratified by Brazil’s Federal Court of Appeal in early May, but the Federal Prosecutors’ Office appealed the ratification.

Overnight, the Superior Court of Justice in Brazil issued an interim order suspending the decision to ratify the settlement agreement.

The effect of the interim order is to reinstate the 20 billion real public civil claim.

“BHP Billiton Brasil intends to appeal the decision of the Superior Court of Justice,” BHP said in a statement this morning.

“In the meantime, Samarco will continue to support the long-term recovery of the communities and environment affected by the dam failure.”

The partners are also facing a separate claim of 155 billion real ($US48.2 billion), made by Brazilian prosecutors in May, based on estimates of the social, environmental and economic impacts.

The value of the claim was based on the costs to repair the damage caused by the Deepwater Horizon spill in the Gulf of Mexico in 2010.

“It is estimated, based on preliminary studies, that human, economic and environmental impacts caused by the disruption of the Fundão dam are at least equivalent to those verified the Gulf of Mexico,” authorities said.

“It does not seem credible, or technique, or morally, that the value of half human, cultural and environmental environment in Brazil is lower than in other countries.”

Vale labelled the claim as “unjustified”.

Despite the news, BHP shares were 3.3% higher at $A19.27 this morning.