UKIP's current and former leaders, Paul Nuttall and Nigel Farage | Ben Stansall/AFP via Getty Images Nigel Farage among 8 UKIP MEPs accused of misusing EU funds MEPs said to have broken rules that ban assistants from working for both the national party and in Brussels.

Eight UKIP MEPs, including the party's former and current leaders, Nigel Farage and Paul Nuttall, could have to pay £500,000 back to the European Parliament after being accused of misusing EU funds, the Guardian reported Wednesday.

The MEPs are suspected of having broken rules that ban European parliamentary assistants from working for the national party. The Parliament's financial watchdog has launched an investigation.

Farage and Raymond Finch will be asked to repay around £84,000 paid to their joint assistant Christopher Adams, according to the report.

Roger Helmer faces the largest bill of about £95,000 for employing UKIP chairman Paul Oakden as his assistant. Farage’s wife Kirsten is also linked to the investigation because she was paid as an MEP assistant while running her husband’s office for the national party.

The other MEPs under investigation are Jonathan Arnott, Louise Bours, James Carver and Margot Parker, the Guardian said.

It added that the total amount owed could be £500,000 if the party is shown to have broken the rules in each case under investigation.

A party spokesman rejected the allegations.