London (CNN)The UK's National Crime Agency has confirmed it is investigating Arron Banks, the backer of the biggest campaign to leave the EU, as well as his associate Liz Bilney and others for electoral law offenses.
Brexit campaigner Arron Banks under investigation, UK confirms
The NCA's involvement comes after the UK's Electoral Commission watchdog referred its own probe into Banks to the agency amid suspicions that Banks' Better For the Country and Leave.EU campaigns may have received money from "impermissible sources," including entities in Gibraltar and the Isle of Man.
Without mentioning allegations of Russian money or interference in the campaign, the commission said it had reason to believe a number of criminal offenses may have been committed.
In a statement, Bob Posner, the commission's Director of Political Finance and Regulation, said: "We have reasonable grounds to suspect money given to Better for the Country came from impermissible sources and that Mr. Banks and Ms. Bilney, the person responsible for Leave.EU, knowingly concealed the true circumstances under which this money was provided."
CNN first reported the NCA was probing Banks in July. According to three people familiar with the matter at the time, the NCA had been handed a cache of Banks' emails detailing meetings he had with the Russian ambassador to the UK, during which he was offered sweetheart deals.
Banks has always denied he took up any of the offers or received money from Russia for the campaign.
In a statement to CNN Thursday, Banks denied any wrongdoing and welcomed the NCA investigation, saying he was "confident that a full and frank investigation will finally put an end to the ludicrous allegations levelled against me and my colleagues."
"I am a UK taxpayer and I have never received any foreign donations," he said.
Banks' spokesman, Andy Wigmore, called the allegations of Russian interference in the Brexit referendum "total rubbish" and said audited accounts of Banks' campaign donations would be made available to the NCA if requested.
Neither Banks nor Wigmore has been contacted by the police on the matter, Wigmore told CNN.
Banks' financial support for Leave.EU in the run-up to the 2016 vote made him the biggest individual donor in British political history. The group won the endorsement of the leader of the UK Independence Party, Nigel Farage, one of the leading pro-Brexit campaigners. According to the latest accounts of Leave.EU, Banks' loan has not been repaid.