WASHINGTON: Kraken, one of the world’s largest cryptocurrency exchanges, is under federal investigation, suspected of violating US sanctions by allowing users in Iran and elsewhere to buy and sell digital tokens, according to five people affiliated with the company or with knowledge of the inquiry.

The Treasury Department’s Office of Foreign Assets Control has been investigating Kraken since 2019 and is expected to impose a fine, said the people, who declined to be identified for fear of retribution from the company.