NIGEL Farage has distanced himself from a former aide who faces up to 20 years in prison in the US after admitting attempting to defraud criminals on the “dark web” by masquerading as a money launderer.

George Cottrell posed as a “financier” on a black-market network where he offered to help transfer the ill-gotten gains of drug traffickers, according to court documents.

However his prospective clients were in fact undercover agents, and Cottrell was arrested as he and the former Ukip leader travelled back to Britain following a trip to the US.

The ex-aide, who is in his 20s, was charged with a string of offences including blackmail, extortion and money laundering. He now faces up to two decades in jail and a fine of up to $250,000 (£203,000) after reaching a deal with prosecutors.

Farage told ITV’s Good Morning Britain: “He’s not an employee, he was a volunteer. He was unpaid. He was helping me do stuff. He’d been part of our party for a couple of years.

“We never had any suspicions about him at all. He faced 21 charges in America, 20 have been dropped. He’s pleaded guilty to a C grade felony. Listen, I can’t be responsible for what everyone around me does.”

Asked if he was disappointed in the former aide, Farage said: “Surprised ... he was 20 years old at the time this happened. Guilt, no guilt, fallen into bad company – I’m not sure.”

A plea agreement filed by prosecutors in Phoenix, Arizona, in December states that Cottrell admitted communicating with the “traffickers” on March 27, 2014. He said he had contacted individuals in Phoenix from London and worked with an associate called “Banker”.

Cottrell said: “I explained various ways criminal proceeds could be laundered – for example, methods to transfer large amounts of cash out of the United States without triggering reporting requirements and ways to disguise the proceeds as legitimate business income for tax purposes.

“I falsely claimed that I would launder the criminal proceeds through my bank accounts for a fee. Rather than launder any of the money, though, Banker and I intended to retain the money.”

In court documents prosecutors said that around March 2014 Banker had advertised “money laundering consultation services” on a clandestine network using software called TOR (The Onion Router).

“Undercover law enforcement agents contacted Banker, posing as drug traffickers seeking money laundering services for approximately $50,000 to $150,000 (£120,000) per month in drug trafficking proceeds,” prosecutors said.

“Banker agreed to help the undercover agents launder their money for a fee, and then proposed that the undercover agents speak with his associate, ‘Bill’.

“The undercover agents talked with Banker and Bill on March 27 2014, via an encrypted group messaging platform. Bill agreed to launder the undercover agents’ purported drug proceeds by transferring the property to offshore accounts ‘with complete anonymity and security’. The undercover agents then met with Bill – later identified as George Swinfen Cottrell – in person in Las Vegas.”

Cottrell was arrested as he returned from the Republican Party convention with Farage on July 22.