Nintendo has confirmed a breach of security on the Japanese version of the Club Nintendo website.
Kotaku reports that the platform holder says it noticed a unusually high number of errors were noticed on the site on July 2nd, at which point it launched an investigation.
That discovered that 23,000 unauthorised log-ins were successfully made from 15m attempts between June 9th and July 4th.
Nintendo has said that it is possible that members' full names, home addresses, phone numbers, and mail addresses were compromised” although the site did not contain any credit card information.
All member passwords have now been reset.