Four men have been arrested by the U.K.'s National Crime Agency (NCA) for drug offenses in connection with their involvement in Silk Road, an Internet underground marketplace for drugs and other illegal items.
The FBI shut down Silk Road, a website that was only accessible through the Tor anonymity network, in September and on Oct. 1 they arrested a man named Ross Ulbricht in San Francisco, who's believed to have been the site's owner and operator.
Hours after the FBI arrested the suspected creator of Silk Road, officers from the National Crime Agency, a new U.K. law enforcement agency that went live Monday, arrested three suspects, two in their early 20s from Manchester and one in his early 50s from Devon.
The three men are among several suspects identified as "significant users" of Silk Road as a result of close cooperation between NCA and American law enforcement agencies. Other U.K. suspects are to be arrested in the coming weeks, the agency said Monday.
The recent arrests are the start of a wider campaign to investigate the "dark" or "deep" Web used by cybercriminals, said Andy Archibald, the head of NCA's National Cyber Crime Unit.
When it was shut down, Silk Road had over 13,000 listings for controlled substances like cannabis, heroin, methamphetamine, LSD, opium, as well as prescription drugs. The site was also used to sell malware, hacking services, stolen bank account information, forged identity documents, firearms and more.
Transactions on Silk Road were done in the Bitcoin virtual currency, the FBI seizing 26,000 Bitcoins from Ulbricht that are estimated to worth $3.6 million. However, authorities claim that more than 1.2 million transactions were conducted on the site from February 2011 to July 2013, generating revenue of $1.2 billion.
The NCA will lead a multi-agency team whose purpose will be to investigate and combat the threat that virtual currencies pose to the U.K. That work is currently being discussed with partners from around the world, NCA said.