Whistleblower Christopher Wylie told lawmakers that the Brexit referendum could have gone the other way if rules hadn't been broken during the campaign.
"I think it is completely reasonable to say that there could've been a different outcome in the referendum if there hadn't been, in my view, cheating," said Wylie, a former contractor at Cambridge Analytica who is now at the heart of the Facebook scandal.
He was giving evidence to a parliamentary committee that's investigating allegations first reported by the Observer that information on millions of Facebook users was scooped up without their consent. Brexit campaigners have denied any wrongdoing.