Claims that the two Leave campaigns worked with the data harvesting firm Cambridge Analytica have been dismissed as baseless in an official investigation by the information watchdog.

The Information Commissioner’s Office has knocked down a series of high-profile allegations levelled against the official and unofficial Brexit groups, confirming it has found “no evidence” to support allegations they used the company’s services.

It comes months after Cambridge Analytica, a UK-based company, became embroiled in a global scandal when it was found to have harvested the personal data of 87 million Facebook users, many of whom had not consented.

Amid a widespread backlash against the firm, which has since shut down, a string of allegations were made over its involvement in the Brexit campaign and association with prominent Leave supporters.

But yesterday, in a wide-ranging report, the ICO confirmed that it had found “no evidence that... CA [Cambridge Analytica] were involved in any data analytics work with the EU Referendum campaigns.”

Its findings were last night seized upon by Brexit campaigners, who have long argued that investigations into wrongdoing during the referendum campaign have been overwhelmingly focussed on the Leave side.

It follows accusations of “Remain bias” levelled against the Electoral Commission, whose chairman said he “regretted the result of the referendum” and complained about “the panoply of Eurosceptic nonsense about the EU”.