THESSALONIKI, Greece (AP) — Greek authorities say they have arrested a Russian man wanted in the United States on suspicion of masterminding a money laundering operation involving at least $4 billion through bitcoin transactions.

Police said Wednesday they arrested the 38-year-old, who has not been officially named, the previous morning in northern Greece in cooperation with US authorities, and seized electronic equipment from his hotel room.

The man has been accused of laundering an estimated $4 billion since 2011 by using the online bitcoin currency. Greek police said he had been directing a criminal organization that owns, operates and manages "one of the largest cybercrime websites in the world."