ARRON Banks has said he is considering legal action against the Electoral Commission after a criminal investigation against the Brexit campaigner and the Leave.EU group he founded was dropped.

The Electoral Commission said the case highlighted an “apparent weakness” in the law which allowed foreign money into British politics.

The National Crime Agency (NCA) launched an investigation into the pro-Brexit campaign group after it was fined £70,000 by the Electoral Commission in May last year. It was found to have overspent during the 2016 referendum campaign.

Yesterday, the NCA said it had found no evidence of criminal offences under electoral or company law by any of the individuals or organisations referred to it by the Electoral Commission.

It will therefore “take no further action against Banks, Leave.EU chief executive Elizabeth Bilney, Better for the Country Ltd or Leave.EU in respect of this specific matter”.

A spokesman for the Electoral Commission said: “We are concerned about the apparent weakness in the law, highlighted by this investigation outcome, which allows overseas funds into UK politics. We have made recommendations that would tighten the rules on campaign funding and deter breaches. We urge the UK’s Governments to act on those recommendations to support voter confidence.

“Significant sums were spent on campaigning at the 2016 EU referendum and it is vital that voters have transparency over the way these campaigns were funded. It is therefore right that suspected offences are investigated by the appropriate authorities, as the NCA has done in this case.”

The NCA said: “There have been media reports alleging that Mr Banks has been involved in other criminality related to business dealings overseas. The NCA neither confirms nor denies that it is investigating these reports.”

Referring to the Electoral Commission’s comments, Banks said: “No overseas money was used in the Brexit campaign, it was my money. We intend to issue a claim against the EC for the decision to refer this matter to the @NCA publicly. We calculate the losses well over £10 million ...”

Banks said he was considering legal action against the Electoral Commission. He tweeted: “We believe the DCMS committee [the House of Commons Commons Digital, Culture, Media and Sport Committee] manufactured this referral with the @ElectoralCommUK to the NCA as part of a political witch-hunt led by anti Brexit MPs. Russia collusion narrative completely destroyed but legal action against the @ElectoralCommUK and those involved will follow.”

Banks said the Electoral Commission had behaved “scandalously”, making “false” and “outrageous” allegations of criminal conduct. “For nearly a year, I have been subjected to an endless media campaign suggesting that I behaved improperly during the 2016 referendum campaign,” he said in a statement. “This is all because the Electoral Commission, having found no impropriety, forwarded my file to the NCA.

“They made false, outrageous allegations that I was not the true source of funds during that campaign and that ‘a number of criminal offences may have been committed’. No wrongdoing of any kind has been found and I intend to take action against those who have behaved so scandalously.”

Brexit Party leader Nigel Farage, who led the Leave.EU campaign during the referendum, said: “The appalling establishment campaign against Arron Banks must now end.”