A close ally to former UK Independence Party leader Nigel Farage has been arrested in the US on accounts of 21 charges including attempted extortion, money laundering and fraud.

George Cottrell, 22, awaits trial and could face years in jail. He is suspected to have offered his services to potential clients via the ‘dark web’ using the alias ‘Bill’.

The Telegraph reported that a team of FBI agents posing as drug traffickers contacted Cottrell in 2014. According to court documents, he promised to launder money for them through his offshore accounts in ‘complete anonymity and security’.

Cottrell met with the undercover agents in Las Vegas and arranged for them to send him £15,500. In addition, he also threatened to expose the ‘drug traffickers’ to the authorities if they did not pay him £62,000-worth of bitcoin, the indictment said.

Custom officials took Cottrell into custody on July 22, when he and Farage landed at Chicago’s O’Hare airport on their way to London’s Heathrow. According to the documents filed at the US District Court in Illinois, Cottrell has a ‘serious, years-long gambling problem, which inherently suggests a strong possibility of irrational risk taking’ and poses a ‘serious flight risk’.

Cottrell, reported to be worth around £250 million, had been working for Farage for free during the Brexit referendum. The Telegraph stated that Farage reportedly was unaware that Cottrell was being watched by FBI agents, and his arrest is thought to have come as a shock.

“George was an unpaid and enthusiastic volunteer for the party over the period of the referendum”, a UKIP spokesman said. “We are unaware of the details of the allegations excepting that they date from a time before he was directly involved in the party.”

Cottrell appeared briefly in court 4 days after he was seized. An FBI spokesman said that he is due to be extradited to Pheonix, Arizona.