A key figure in the campaign to take Britain out of the EU has privately acknowledged that they deliberately used “outrageous” and “provocative” tactics to keep immigration at the top of the referendum debate.

Speaking to an academic researcher, Andy Wigmore appeared to compare the process to the “very clever” propaganda techniques of the Nazis.

Mr Wigmore was communications director for the Leave.EU campaign fronted by then Ukip leader Nigel Farage and funded by millionaire Arron Banks.

His comments were described as “particularly concerning” by Damian Collins, the chairman of the House of Commons Digital, Culture, Media and Sport Committee, which is conducting an inquiry into the phenomenon of “fake news”.

But Mr Wigmore retorted that the committee itself was “complicit in creating a fake news agenda designed to bring down Brexit”.

In interview recordings released by the committee, Mr Wigmore can be heard discussing Leave.EU’s contacts with the controversial company Cambridge Analytica, which has come under fire over the use of Facebook users’ personal data in Donald Trump’s race for the US presidency.

Mr Wigmore states that CA did no work for Leave.EU after it failed in its bid to be named lead Brexit campaigner.

But he said that Leave.EU “copied” CA’s methods for pinpointing groups believed to be susceptible to specific messages. And he suggested that actuaries from Mr Banks’s Eldon Insurance used probability calculations to identify areas where Mr Farage should campaign.

Mr Wigmore was among a number of figures from the Leave campaign and companies linked to Cambridge Analytica who spoke to Essex University researcher Emma Briant for an upcoming book on the Trump campaign.

He told Dr Briant that Leave.EU “completely, completely, completely” copied Trump’s campaign technique of making attention-grabbing and controversial comments.

“The only way we were going to make a noise was to follow the Trump doctrine, which was: the more outrageous we are, the more attention we’ll get, and the more attention we get, the more outrageous we’ll be,” said Mr Wigmore. “And that’s exactly what we did.”

He admitted that the campaigners were “unsure constantly if we were doing the right thing” and were concerned they would be blamed for creating “a wave of hatred and racism”.

After the murder of Labour MP Jo Cox, he said the campaign thought that “maybe we have gone too far”, with Mr Farage fearing Leave would lose the referendum vote a few days later. But he said that in the event there was “no shift in the dial” from voters outside London who “understood” the message behind Ukip’s controversial Breaking Point poster.

Nigel Farage launches the controversial Breaking Point poster during the referendum campaign (Philip Toscano/PA)

Mr Wigmore told Dr Briant: “The propaganda machine of the Nazis, for instance – you take away all the hideous horror and that kind of stuff, it was very clever, the way they managed to do what they did.

“In its pure marketing sense, you can see the logic of what they were saying, why they were saying it, and how they presented things, and the imagery.

“And looking at that now, in hindsight, having been on the sharp end of this campaign, you think: crikey, this is not new, and it’s just … using the tools that you have at the time.”

His comment was echoed by the chief executive of CA’s parent company SCL Group, Nigel Oakes, who told Dr Briant that Mr Trump “leveraged an artificial enemy” in the shape of the Muslims in the same way that Adolf Hitler played on pre-war German hatred for Jews.

Mr Oakes insisted that CA did not work for the Leave.EU campaign, but had made presentations as part of a bid for a contract had the group been designated lead campaigners.

He also told Dr Briant that CA’s suspended CEO Alexander Nix had approached Julian Assange to offer to help him to release leaked emails from Hillary Clinton during the presidential campaign, but was turned down by the Wikileaks founder.

Mr Collins said that the recordings gave a “unique insight” into the thinking of those at the top of the Leave.EU campaign, and said references to the Nazis were “particularly concerning”.

“Andy Wigmore states that he believes that the propaganda techniques of the Nazi’s were ‘very clever’,” said Mr Collins. “He also confirms that exploiting voters’ concerns about immigration was central to their campaign during the Brexit referendum.

“Given the extreme messaging around immigration that was used during the referendum campaign, these statements will raise concerns that data analytics was used to target voters who were concerned about this issue, and to frighten them with messaging designed to create ‘an artificial enemy’ for them to act against.”

Mr Collins said Dr Briant’s research made clear that Leave.EU benefited from their work with CA, and said the campaign had questions to answer about how it developed its database.

But Mr Wigmore said that the release “sounds like another attempt to try and justify a committee that is desperate to try and find any excuse to undermine the referendum”.

He said his conversations with Dr Briant were not for publication and described their release as “wilful deception and trickery”.

Leave.EU chairman Arron Banks accused the committee of creating fake news (Jonathan Brady/PA)

The Nazis came up for discussion “in a historical context” in reference to the scare tactics being used by the Remain campaign, said Mr Wigmore. He repeated Leave.EU’s denial that it used CA, and added that “no actuaries were employed on our campaign”.

“Immigration was the key issue in pretty much all polling,” said Mr Wigmore. “Facts are not scare tactics, if that’s what people feel is their concerns, and it was our opinion that we had to keep that top of the agenda in line with our polling and the strategy of Nigel Farage.”

Mr Banks said that the committee was “too scared to call me to give evidence”.

And he added: “Monty Python couldn’t make this up: a Parliament Committee inquiry into fake news creating fake news to then investigate fake news.”

CA said Mr Oakes had never worked for the company and “did not work on the Trump campaign in any way whatsoever”.

A spokesman said: “Mr Oakes was speaking in a personal capacity about the historical use of propaganda to an academic he knew well from her work in the defence sphere. These are comments that have already been reported on in the media in the past few years.

“Like much of the reporting surrounding our company, Dr Briant’s ‘explanatory essays’ contain uncontextualized comments, unsubstantiated assertions and the joining together of dots to establish a picture that suits the authors.”