A Sunday Telegraph investigation earlier this year found that around 500,000 UK customers were overcharged by around £40 million for inflated vehicle repair costs of up to 300%. The paper now says that ‘hundreds’ of its readers have complained of unreasonably large charges for minor repairs while abroad.

The Telegraph reported in the summer how it had uncovered an alleged secret system of rebates that inflated repair costs. Europcar has now forced suppliers to change practice but admitted to the paper that the potential compensation value was around £40 million - £10 million more than originally estimated.

If the KPMG investigation concludes there have been other abuses, the company could face a much higher bill.

Europcar told The Telegraph that it regularly reviewed terms and conditions “ as an ongoing process…to be in line with legislation with every country where we operate”.

It added: “We receive input on that process from our third party advisors such as KPMG.”