Electronics giant Sony has revealed that it suffered a significant data breach just one day before the recent high profile hack on its online gaming system, and that a further 25 million users’ details “may have been stolen”.

The company said it discovered this breach while engineers were reviewing their systems in the wake of the recent breach of the PlayStation Network (PSN). It occurred over the 16th and 17th of April, just a day before the PSN was comprimised.

The newly revealed breach affected the Sony Online Entertainment (SOE) PC gaming network, a separate entity to PSN network that hosts games between PCs rather than consoles.

Stolen details include names and addresses of subscribers, as well as email addresses, birthdays and genders. Sony said that older information may have also been stolen, including credit and debit card numbers and direct debit details of subscribers in Germany, Spain, Austria and the Netherlands. However, the company said that their main credit card databases were uncompromised.

Sony has taken down the entire SOE network in response to the breach. “With the current outage of the PlayStation network and Qriocity services and the ongoing investigation into the recent attacks, SOE had also undertaken an intensive investigation into its system," the company said in a statement. "Upon discovery of this additional information, the company promptly shut down all servers related to SOE services while continuing to review and upgrade all of its online security systems in the face of these unprecedented cyber-attacks. ”

The SOE PC games network hosts online games between PCs rather than consoles. In total, between the 16th and 19th of April, Sony may have had details of over 100 million users stolen.