A New York Times report has it that the US Treasury Department has been investigating crypto exchange Kraken since 2019.
The report also has it that the Treasury Department is expected to impose a fine on the cryptocurrency exchange.
The firm may have violated U.S. sanctions by allowing users in Iran, Cuba and Syria to buy and sell digital assets.
The Treasury Department Office of Foreign Assets Control is handling the investigation.
Kraken would be the largest American crypto firm to be hit by enforcement action by the office.
Iran, as well as Syria and Cuba, are under US sanctions. Sanctions against Iran have been in place since 1979.