Sony has warned users of its PlayStation Network that hackers may have stolen their personal information, including credit card details.

According to Sony, a hacking attack on its PlayStation Network last week may have resulted in the names, addresses and possibly credit card details of 77 million people being stolen.

Sony is now planning to email its PlayStaion Network users warning them that their personal details may be in the hands of hackers.

The PlayStation Network was suspended last Wednesday, but Sony kept quiet about what happened for a week.

Today, the Japanese electronics titan admitted that there had been a serious security breach. The company said that the data may have fallen into the hands of an “unauthorised person” following a hacking attack on its online service.

In a statement Sony said an “illegal and unauthorised person” obtained PlayStation Network users’ names, addresses, email address, birthdates, usernames, passwords, logins, security questions and more.

Sony said there was no evidence credit card numbers were stolen by the hackers but warned users it could not rule out the possibility.

“Out of an abundance of caution, we are advising you that your credit card number (excluding security code) and expiration date may have been obtained,” the company said.

PlayStation Network provides online video gaming services and allows streaming of films and music. It has about three million British users.

The hacking attack on Sony’s PlayStation Network is one of the largest and most high profile online data thefts to be reported. It raises concerns about identity fraud because of the variety of user information stolen and because people often use the same password for all of their online accounts.

Sony is likely to face questions about when it knew that customer data had been stolen and why it waited so long before issuing a statement.

In an email, Sony warned PlayStation Network users to be aware of possible fraudulent emails, telephone calls and letters asking for further personal information.

The company has not said when the PlayStation Network service will be retored.