In the news report, an undercover investigator posing as the son of an American donor is recorded raising a concern that his father wouldn't be able to directly donate to the party within the law.

Electoral law states that to be a permissible donor to a UK political party you must be a UK registered voter, or a company registered in the UK.

Jukes appears to suggest that the donation could be in the UK-based son's name, although the money would have come from his American father.

Elsewhere, James Orr, the party's head of policy suggests that the father could pay for opinion polling to support one of Reform's campaigns.

Farage and Jukes were also filmed at a lunch in Clacton where it is suggested the US donor, who was being played by an actor, gives £500,000 to Reform through his son.

Farage told the BBC he "frankly wasn't listening" to the discussion about the potential donation. Channel 4 News has said the payment was never made.

He dismissed the comments made by his aide in the film as "loose pub talk including a couple of boasts that simply were not true".

Jukes has denied "any wrongdoing" and said he had "stepped back from politics in order to clear my name".

Last week, Orr told Sky News he would cooperate with the party's internal investigation "fully".

The Met had already been investigating whether payments to Reform in the weeks before the last election complied with donation laws.

The probe is examining donations given directly to the party by Fiona Cottrell, mother of longstanding Nigel Farage ally, George Cottrell.

It is also examining payments from a company controlled by Reform's deputy leader Richard Tice, which received £1m from Fiona Cottrell in June 2024.

A Verbatim Investigations spokesperson said: "Verbatim will cooperate with the police's investigation."

Labour Party Chair Bridget Phillipson said: "Farage needs to wake up and realise the buck stops with him.

"Reform's failure to take responsibility for their actions shows just how unfit they are for office."

The Liberal Democrat's Cabinet Office spokeswoman Lisa Smart said: "Every Reform MP urgently needs to state whether they or their campaigns have benefited from any foreign money."

Zack Polanski, leader of the Green Party in England and Wales, said: "Nigel Farage and Lee Anderson hoped they could pin all this on two of their most senior advisors, but they have more questions to answer about how much they knew."