Like cash, Bitcoins can be used in transactions without providing a record of its source. The virtual currency, whose value at one point topped $1,000, has been used for all types of online purchases, both legal and illegal.

The Silk Road, an eBay-like Bitcoin exchange that included listings for guns and heroin, was recently shut down by the U.S. authorities.

Online casinos will also be brought into the government's existing money laundering rules, the federal government said.