More than a quarter of a million people using the payday loan site Wonga may have had their private data stolen.

The site has reported that more than 250,000 customers may have had their personal details accessed following a data breach.

Wonga have claimed they are “urgently investigating illegal and unauthorised access” involving the details of customers in the UK and in Poland. The breach could affect as many as 270,000 people who use, or have used, the payday lender at some point, including 245,000 UK customers.

Customers who may have been affected will have been sent a message from the lender saying: “We believe there may have been illegal and unauthorised access to some of your personal data on your Wonga.com account.”

Data breached may include names, emails, addresses, phone numbers, the last four digits of your card number or the account number and sort code.