Washington (CNN) An individual who volunteered for a Brexit campaign effort said the organization broke the law, and in turn, is arguing the referendum vote "wasn't legitimate," according to the United Kingdom's Channel 4 News.

Shahmir Sanni told Channel 4 that the organization "Vote Leave" coordinated spending over the legal limit, using a Canadian data firm called Aggregate IQ, otherwise known as AIQ. British election law enforces a spending cap on donations, which includes when groups coordinate donations.

"I know that Vote Leave cheated, that people had been lied to and that the referendum wasn't legitimate," Sanni said in an interview with the broadcaster.

Separately, in an interview with The Observer , Sanni claims a donation of £625,000 by Vote Leave to another Brexit group, "BeLeave," was funneled to AIQ.

In a tweet Saturday, UK Foreign Secretary Boris Johnson called the stories by Channel 4 and The Observer, "utterly ludicrous, #VoteLeave won fair and square -- and legally."

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