G4S security problems 'biggest failure of games'

More than 1,000 extra troops have been deployed to bolster security at the Olympic Games.

Earlier this month 3,500 personnel were drafted in after security provider G4S admitted it was short of staff.

Paul Deighton, Chief Executive of the London 2012 organising committee, Locog, admitted that the problems at G4S have been the biggest failure of the games.