The accounts of up to 250,000 Wonga customers have been hacked.

The police and Financial Conduct Authority are investigating the illegal and unauthorised access to the personal data.

The payday loan company is contacting people it knows have been affected by the data breach.

The stolen information may have included one or more of the following: name, e-mail address, home address, phone number, the last four digits of the customer's card number (but not the whole number) and/bank account number and sort code.

The firm says it does not believe Wonga account passwords were taken and accounts should be secure.

"However if you are concerned you should change your account password. We also recommend that you look out for any unusual activity across any bank accounts and online portals," it says.

Customers whose details have been taken should

  • Alert their bank and ask them to look out for any suspicious activity
  • Consider changing their Wonga password
  • Be aware of anyone who calls and asks to disclose any personal information regardless of where they say they are from. If this happens, hang up.
  • Be suspicious of any unsolicited emails or texts, even if it appears to be from a company they know of. Do not open attachments or click on links within unsolicited emails

Victims of fraud or cyber crime should report it to Action Fraud at http://www.actionfraud.police.uk/report_fraud

Wonga, which apologised for the inconvenince and concern caused, adds: "We take issues of customer data and security extremely seriously.

"Cyber attacks are, unfortunately, on the rise. While Wonga operates to the highest security standards, these illegal attacks are unfortunately increasingly sophisticated."