Kaz Hirai, the head of Sony's gaming division, will speak to journalists in Tokyo and provide the findings of an investigation into the hack of its online gaming service, said Sony. Hirai will also detail the PlayStation Network's system security measures and service restoration plan.

The PlayStation Network, which acts as an e-commerce and online gaming platform for the PlayStation 3, has been unavailable for more than a week. Sony took it offline after discovering an attack on the system had taken place.

Sony's main avenue of communications with its customers to date has been via messages on its regional websites. But many questions are yet to be answered.

Chief among them is the size of a data leak that took place. Sony said customer information was lost, but its unclear if it affects all 77 million customers of a subset of them. The status of customer credit card numbers is also uncertain. Sony previously said it hadn't uncovered evidence of a theft of card numbers, but it advised users to nonetheless be on the look out for suspicious transactions.

Also in the spotlight is Sony's apparent slowness in taking the network offline and informing customers. it became aware of an intrusion on April 19 but the network wasn't taken offline until a day later. It was two further days until Sony acknowledged it had been hit by an attack, and only on April 26 did it warn customers their information may have been stolen.