When the Federal Bureau of Investigation nabbed alleged Silk Road founder Ross Ulbricht, they left behind one giant piece of the puzzle - the mastermind's hidden stashes of Bitcoins that may collectively be worth as much as $80 million.

When the FBI took down the Deep Web underground market on October 1, they seized nearly 30,000 Bitcoins in the process. Those funds are now worth roughly $6 million based on current exchange rates and on Friday, the FBI located and seized a stash of 144,000 Bitcoins believed to have belonged to Ulbricht.

In total, the FBI is now in control of 174,000 or so Bitcoins which is about 3.15 percent of all Bitcoins in circulation. What's more, another stash of 110,000 Bitcoins worth $22 million has been potentially tied to Ulbricht. For the FBI to gain control over those funds, however, they will need more than just the address of the Bitcoins.

Specifically, they would need to have access to the private key for the wallet. That key could very well be hidden away on a computer somewhere - anywhere - that may or may not have been in Ulbricht's possession at the time he was arrested. Of course, it's also entirely possible that the FBI already has the key and has yet to move the funds to their own account.

An FBI spokesperson previously said they will likely exchange the Bitcoins for dollars once Ulbricht's trial or settlement is over with.