Brexit group and '˜key player in referendum' hit with £70,000 fine

The group, co-founded by former Ukip backer Aaron Banks, overspent by at least £77,380 - 10 per cent over the limit for non-party registered groups - an investigation found.

The commission said the actual figure ‘may well have been considerably higher’, adding that the group had presented ‘incomplete and inaccurate’ information about spending.

But it said it found no evidence that controversial tech firm Cambridge Analytica had made donations or provided paid-for services, and its role was limited to ‘initial scoping work’.

It also said that a case has been referred to the Metropolitan Police.

Bob Posner, the Electoral Commission’s director of political finance and regulation, and legal counsel, said: ‘The rules we enforce were put in place by Parliament to ensure transparency and public confidence in our democratic processes.

‘It is therefore disappointing that Leave.EU, a key player in the EU referendum, was unable to abide by these rules.

‘Leave.EU exceeded its spending limit and failed to declare its funding and its spending correctly. These are serious offences.

‘The level of fine we have imposed has been constrained by the cap on the Commission’s fines.’