Leave.EU – the largest pro-Brexit campaign in Britain, set up and run by the millionaire Arron Banks – have been accused of hijacking personal data during the Referendum campaign.

A whistleblower who worked for UKIP during the Brexit campaign has told this programme how he was ordered to hand over the personal details of more than a 100,000 UKIP supporters to a team employed by Mr Banks – in what could have been a breach of the law.

Both Leave.EU and UKIP deny they did anything wrong but tonight the whistleblower has made a formal complaint to the Information Commissioner. Ed Howker has this exclusive report.