Chinese hacking of US defence systems 'a major breach'
29 May 2013 Last updated at 05:11 BST
Chinese hackers have accessed designs for more than two dozen US weapons systems, a US newspaper has reported.
Designs for combat aircraft, ships and missile defences were among those compromised, a Pentagon paper found, the Washington Post reported.
Steve Durbin from the Information Security Forum told BBC News that the breach was "a major breach and a major concern".