A $1bn bail application by alleged Silk Road founder Ross Ulbricht has been rejected by a US federal judge.
US district Kevin Fox said there was "clear and convincing evidence" that Ulbricht, who is accused of being the administrator of the online black market's operation, would be dangerous if released from custody.
Assistant attorney Serrin Turner alleged that Ulbricht was behind a total of six murder contracts. The 29-year-old suspect paid a total of $500,000 to would-be hitmen he contacted online, prosecutors claimed.
Silk Road - which was shut down by the FBI and reopened on the same anonymous Tor network by an administrator using the same moniker as Ulbricht, "Dread Pirate Roberts - operates on the deep web - which cannot be found by standard search engines - and allows people to buy and sell anonymously a range of illegal items including drugs, counterfeit money, guns and hitmen.
After his arrest by the National Crime Agency in San Francisco, Ulbricht appeared in court to deny all charges. They included money-laundering, computer hacking, drug-trafficking and soliciting a Silk Road user to murder another member of the forum.
Ulbricht's family and friends had pledged more than $1bn towards bail and supporters raised $500,000 through online fundraising.
The judge refused to set bail, ruling that Ulbricht had the means to flee.