It offered the Mozambique property in 2011 for $3.7bn (£2.8bn) and bought them a few years later for $50m.
The mining agency has said it will “vigorously guard” the costs.
The firm become also fined £27m by means of UK authorities for breaching disclosure policies over the African coal purchase.
Both the United States and UK actions relate to the Mozambique funding made by the mining firm six years in the past.
A lawsuit filed in the US accuses Rio Tinto, its former chief executive Thomas Albanese and ex-leader economic officer Guy Elliott of failing to follow accounting standards and agency rules to as it should be fee and file the belongings.
The US Securities and Exchange Commission argues that quickly after the deal changed into finished, Rio Tinto discovered that the projects could produce much less coal, and of a lower satisfactory, than predicted.
“Rio Tinto’s top executives allegedly breached their disclosure duties and company obligations by way of hiding from their board, auditor, and buyers the important fact that a multi-billion greenback transaction was a failure,” SEC Enforcement Division co-director Stephanie Avakian said in a announcement.
By making misleading claims the Anglo-Australian miner – one of the international’s biggest – turned into able to enhance $five.5bn from US buyers, the SEC said.
Rio Tinto stated it “intends to vigorously shield itself towards these allegations”.
The firm brought in a assertion it believes the “SEC case is unwarranted and that, while all the facts are taken into consideration by the court, or if essential through a jury, the SEC’s claims may be rejected.”
As a end result of the charges, Guy Elliott has resigned from his new task as non-executive director of oil giant Royal Dutch Shell.
In a announcement, Shell stated: “We hope he satisfactorily resolves the ones proceedings and, that in that event, he would love to be taken into consideration for rejoining the Board.”
Largest ever UK high-quality
The miner one by one reached a settlement with UK regulators for disclosure failures tied to the Mozambique investment.
It agreed to pay the Financial Conduct Authority £27 million to settle claims that it breached accounting regulations in reference to the African coal property.
The FCA stated the quality is the biggest ever imposed on a company for a list-policies breach.