Mr Banks allegedly discussed a potential business deal involving six Russian gold mines with ambassador Alexander Yakovenko, according to a report in the Sunday Times.
Millionaire Brexit funder Arron Banks risked the wrath of MPs today by waking out of his committee grilling because he has a lunch date. Banks met with Moscow's United Kingdom ambassador three times, but says he did not take Russian money.
Mr Banks said he first met the Russian ambassador over a "boozy lunch".
Arron Banks and Andy Wigmore, who ran the Leave.Eu pro-Brexit referendum campaign, arrive to give evidence to the Digital Culture Media and Sport Parliamentary Committee in London, Britain, June 12, 2018.
The campaigner and Leave.EU communications chief Andy Wigmore are under fire for alleged links to Russian Federation.
Referring to claims that the police could be asked to investigate, Mr Banks said: "I would like to know what the police are going to investigate".
The Leave.EU founder told MPs that no money from his overseas business interests formed part of his political donations and he was "crystal clear" about the rules. "But I think we've been as open as we could be with the issues you've raised".
Asked if he believed there was any attempt by Russian Federation to influence the outcome of the 2016 vote, Mr Banks said it was "possible" but he believed it was confined to a few hackers and computer bots at a "low level".
"You can join us if you want".
"I met with him, I'm a businessman, why shouldn't I?" I structure everything legally.
"Clearly that's nonsense", he said. Farage: "Were you "reporting back" to the Russian Ambassador?"
Meanwhile, Mr Wigmore told MPs he initially met Russian officials at a UKIP conference to talk about bananas in his role as a diplomat for Belize and had since met Russian figures "many times".
But after more than three hours of questioning from members of the committee about his alleged involvement with Russia Mr Banks stood up and announced he would leave to attend a "luncheon meeting".
Cambridge Analytica, which was hired by Trump in 2016, has denied its work on the US president's successful election campaign made use of allegedly improperly harvested data - but questions have since been raised over any role in other votes.
He said: "I was trying to find investors to look at perhaps buying a banana farm which had got into trouble because of its owner. and as a effect Belize couldn't sell its bananas in places like the United States or the United Kingdom".
MPs repeatedly questioned Banks, an insurance entrepreneur, about the sources of his money, prompting Banks to deny any of his wealth that he used to pump at least £9m of loans and donations to the Brexit campaign was from Russian Federation.