A leading campaign group supporting Donald Trump should face an official probe into its role in a fundraising scandal exposed by the Telegraph, one of the US’s most senior election lawyers said.

Lawrence Noble, who was general counsel at the US Federal Election Commission (FEC) for 13 years, said Jesse Benton, former chief strategist at the Great America PAC, was clearly “soliciting foreign national money” from a fictitious Chinese donor in recordings by undercover reporters.

His actions demonstrated “clear violations” of the Federal Election Campaign Act, which the PAC and Eric Beach, its co-chair, who referred Mr Benton to the reporters, could also have breached.

Mr Noble reviewed recordings of discussions with Mr Benton, who said he was acting as a “consultant” to the Great America PAC, one of the leading "independent" groups organising television advertisements and grassroots support for the Republican nominee.

On Monday the Telegraph exposed how Mr Benton had sought to channel $2 million (£1.6 million) from a Chinese donor into the PAC, one of the leading “independent” organisations supporting Mr Trump’s campaign. He said he had previously helped US donors conceal donations.