Brexit campaign funder Arron Banks referred to the National Crime Agency for suspected offences in the run-up to the 2016 EU referendum.

Banks, who also bankrolled UKIP under the leadership of Nigel Farage, is accused of concealing the true source of £8 million donated to the referendum campaign.

Banks is accused of using money from a company he owns called Rock Holdings Limited. This company is registered in the Isle Of Man, making it an impermissible source of funding.

The businessman has been referred to the agency by the Electoral Commission following an investigation into allegations that Banks had breached electoral law.

Banks has denied any wrongdoing.

LONDON — One of the main funders of the Brexit campaign, the businessman Arron Banks, has been referred to the National Crime Agency over "multiple suspected offences" relating to funding during the EU referendum campaign.

Banks — the millionaire businessman who funded UKIP during Nigel Farage's leadership — is to be investigated for alleged criminal offences along with Leave.EU, the pro-Brexit campaign group he funded.

The Electoral Commission announced on Thursday morning that it had referred Banks, senior campaigner Elizabeth Bilney, and Better For The Country, the group which ran Leave.EU, to the National Crime Agency.

Banks is accused of falsely claiming to be the source of £8 million that was loaned to the campaign group Better For The Country and put towards Leave.EU campaigning leading up to the 2016 vote.

In a statement, Banks said: "I am pleased that the Electoral Commission has referred me to the National Crime Agency.

"I am confident that a full and frank investigation will finally put an end to the ludicrous allegations levelled against me and my colleagues."

He added: "There is no evidence of any wrongdoing from the companies that I own. I am a UK taxpayer and I have never received any foreign donations. The Electoral Commission has produced no evidence to the contrary."

In a statement the Commission say they have reason to believe that:

Mr Banks was not the true source of the £8m loans made to Better for the Country.

Loans to Better for the Country, on behalf of Leave.EU involved a non-qualifying or impermissible company – Rock Holdings Limited, which is incorporated in the Isle of Man.

Arron Banks, Elizabeth Bilney and others involved in Better for the Country, Leave.EU and associated companies concealed the true details of these financial transactions.

A number of criminal offences may have been committed.

They added that "due to multiple suspected offences, some of which fall outside the Commission’s remit, the Commission has referred this matter and handed its evidence to the National Crime Agency."

In a statement published on Thursday, the Electoral Commission said: "A number of companies and individuals have been referred to the National Crime Agency for suspected criminal offences committed during the EU referendum.

"Following its investigation into funding for the 2016 EU referendum, the Electoral Commission has referred: Better for the Country, the organisation that ran the Leave.EU referendum campaign; Arron Banks; Leave.EU; Elizabeth Bilney; and other associated companies and individuals. The National Crime Agency has now launched a criminal investigation.

Nigel Farage and Arron Banks in Bristol in October 2014. Matt Cardy/Getty

"The investigation focused on £2m reported to have been loaned to Better for the Country by Arron Banks and his group of insurance companies and a further £6m reported to have been given to the organisation, on behalf of Leave.EU, by Arron Banks alone.

"£2.9m of this money was used to fund referendum spending on behalf of Leave.EU and donations to other campaign groups during the EU referendum."

Leave.EU spokesperson Andy Wigmore told the Guardian: "It's completely to be expected. It will finally bring a head to all these crazy allegations made about us. We’re not worried."

Leave.EU was a separate group to the official pro-Brexit campaign, Vote Leave.