Nintendo Co. has warned the personal information of its customers in Japan may have been exposed following a massive unauthorized breach of its member website.

The data include the names, home addresses, phone numbers and email addresses of Club Nintendo members, the game console and software maker said in a press release Friday.

The company said it has not confirmed any misuse of the information so far. There are around 4 million Club Nintendo members in Japan.

Nintendo confirmed there had been around 15.46 million fraudulent login attempts from June 9 through Thursday, of which 23,926 were successful.

The Kyoto-based company said it has suspended the accounts and passwords used in the unauthorized access and is calling on members whose data may have been illegally accessed to change their passwords.

The service for registered Nintendo customers who have purchased the company's consoles and software allows members to earn points that can be redeemed for such rewards as CDs.