The agency's FinCEN unit has issued an order prohibiting certain transmittals of funds involving Bitzlato by any covered financial institution, it said in a statement.

Reuters was unable to immediately locate contact information for Bitzlato.

By midday Wednesday, Bitzlato's website was replaced by a notice saying that the service had been seized by French authorities "as part of a coordinated international law enforcement action."

(Reporting by Daphne Psaledakis, Raphael Satter, Kanishka Singh, Chris Prentice)