Volunteer Shahmir Sanni told Sky News there was “no way no one knew” about a £625,000 donation made by Vote Leave to a youth Brexit group called BeLeave.
He claims the money was donated in the last two weeks of the referendum period but that Vote Leave retained control over how the cash was spent – an arrangement which would represent a breach of electoral rules.
He said: “I’m a big fan of Michael Gove myself but I find it highly doubtful that you wouldn’t know that enormous amount of spending was given to a campaign.”
Mr Sanni said Mr Gove – along with other pro-Brexit MPs – were “in the office very often” and that “there’s no way no one knew about BeLeave”.
He added: “Everyone was aware BeLeave was a Vote Leave outreach group.”
When pushed on whether Mr Gove would have know about any possible payments, Mr Sanni said he “highly doubted” those who were “best friends” with Vote Leave campaign director Dominic Cummings were “not aware”.
He added: “Just to be clear – the money actually never touched the BeLeave bank accounts.”
Mr Gove told Sky News earlier he was unaware of a donation made by Vote Leave to BeLeave until after the 2016 referendum had concluded, despite being the co-convener of the campaign committee tasked with ensuring all pro-Leave groups were working together effectively.
He said: “I wasn’t involved in the day-to-day running of the campaign, I was out there making the case for leaving the EU rather than managing the hidden wiring of the campaign.
“But I think this case has been investigated twice by the Electoral Commission since it occurred and I think on both those occasions the Electoral Commission said it’s quite right that one campaign can donate to another organisation, and indeed my understanding is that the Remain campaign did pretty much the same thing.”
He said his role as co-convener of the campaign committee saw him “make sure that all of the politicians that were out there making the case and who were part of the Vote Leave coalition were working effectively together and I’m afraid we only met weekly rather than daily”.
Labour and the Liberal Democrats have called for the police to investigate the claims by Mr Sanni that Vote Leave “cheated” in order to secure victory in the referendum.
Key Brexiteer Boris Johnson has rubbished the claims as being “utterly ludicrous” – and Vote Leave denies any wrongdoing.
An Electoral Commission spokeswoman has said: “The commission has a number of investigations open in relation to campaigners at the EU referendum; it does not comment on live investigations.”