Sony is still investigating the security breach that downed its PlayStation Network and Qriocity online services, but expects the gaming network will be back in operation this week, a company exec told media Sunday afternoon in Tokyo.

Full service on PlayStation Network to resume this week with online gaming, full service expected to be restored by mid-May, Executive Deputy President Kazuo Hirai told media at a briefing that ended just minutes ago.

The investigation continues, however; Hirai said Sony has requested help from the U.S. FBI to investigate the network intrusion. Sony shut down the network April 20 after realizing on April 18 that it had been hacked, but did not disclose the breach until April 22.

Networking gaming and music unlimited will apparently be the first services to go back online, according to Sony. It appears SonyStyle is a different system and not affected by this.

Sony has drawn criticism from users and from disparate agencies, including the U.S. Department of Homeland Security, the U.S. Congress and officials at Taiwan's capital, Taipei.

More information will follow in an update to be posted shortly.

Reporting by Martyn Williams, IDG News Service, in Tokyo.