Following the shut down of illicit marketplace Silk Road by the FBI, the newly formed National Crime Agency has moved to arrest four Brits suspected of using the platform to deal drugs.
Three men in their twenties were arrested in Manchester on suspicion of supplying drugs and another man in his early fifties was arrested in Devon.
According to reports in the Telegraph, further arrests are expected in the UK.
These criminal areas of the internet aren't just selling drugs.
Silk Road was shuttered after its alleged operator, Ross Ulbricht, was arrested in San Francisco by the FBI. Silk Road allowed drug dealers to sell their wares and take Bitcoins as payment.
Ulbricht, who went by the nickname "Dread Pirate Roberts", appeared in court last Friday accused of running Silk Road.
NCA chief Keith Bristow said the use of Tor to hide their dealings did not stop the authorities from tracking them down.
"It is impossible for criminals to completely erase their digital footprint. No matter how technology-savvy the offender, they will always make mistakes and this brings law enforcement closer to them," he told the Telegraph.
Andy Archibald, head of the newly formed NCA's National Cyber Crime Unit, said: "These criminal areas of the internet aren't just selling drugs. It's where fraud takes place, where the trafficking of people and goods is discussed, where child abuse images are exchanged and firearms are traded."
According to FBI filings, Silk Road managed to amass nearly a million users before the authorities pulled the plug. However, it is not known how many were UK users.
Meanwhile, the FBI have encountered problems trying to seize 600,000 Bitcoins, worth around $80 million, from Ulbricht as his Bitcoin wallet is held separately and is encrypted, according to a report by Forbes.
