“We have not yet determined exactly how the Bitcoins will be converted and liquidated,” said Manhattan U.S. Attorney Office spokesperson Jim Margolin.

There is no legally certified U.S. Bitcoin exchange, and I doubt the feds want to sell the coins via Mt. Gox, which got in legal trouble last year for operating in the U.S. without a license, or via BTC-e, the mysterious exchange based in Bulgaria. It’s likely that the U.S. Marshals will instead auction off the Bitcoins as if they were Bernie Madoff’s penthouse or a drug dealer’s cars. When the FBI first seized the coins in October, they were worth about $6 million; they’re now worth four times that. This is a bust that keeps on paying off. The proceeds will go to the U.S. Treasury.

As for the over 144,000 bitcoins seized from Ross Ulbricht, who is alleged to be Silk Road founder Dread Pirate Roberts, they will remain in the FBI’s very large wallet for now.

“Ulbricht has filed a claim in the civil forfeiture action, asserting that he is the owner of the Bitcoins found on his computer hardware, and contesting the forfeiture of those Bitcoins,” notes the Manhattan U.S. Attorney’s press release. Ulbricht is facing drug, computer hacking and money laundering conspiracy charges; he claims that he is not the creator of the Silk Road, but that the over $100 million worth of Bitcoin found on his computer does belong to him.