Troops drafted in to protect London 2012 venues after the G4S fiasco make up 50 per cent of security personnel stationed at the Olympic Park.
Organisers were forced to turn to the military when the embattled security contractor admitted it did not have enough staff to patrol the Games just weeks before they were due to begin.
Some 4,700 service personnel are now plugging the gaps - making up half of security staff at the venue in Stratford, east London.
Paul Deighton, chief executive at Locog, said: "The mix on the park, for example yesterday, in terms of the different groups running security, we had about 50 per cent military, 40 per cent G4S - our private security firm - and about 10 per cent volunteers."
He said there have been "absolutely no issues" for people coming into the park through the pedestrian search areas where G4S was contracted to conduct physical searches and operate X-ray machines.
"What we've done in terms of training, capacity and management of that ... has been very effective," he added.
His comments came as it emerged soldiers guarding Olympic sites in London were being housed in accommodation branded "absolutely disgusting".
Relatives of the personnel from 1st Battalion The Princess of Wales's Royal Regiment (1PWRR) are being housed at Tobacco Dock near Tower Bridge, where around 500 of the men sleep on camp beds.
Fiona Mason, from Fair Oak in Hampshire, whose son Paul, 21, is in the regiment, told the Southern Daily Echo the men were "treated better in the desert".
The total number of military personnel involved in Olympics security is now more than 18,000, including 11,000 helping secure Games venues, with the rest working in specialist roles.
G4S chief executive Nick Buckles has faced calls to resign from his £830,000-a-year job after the blunder.
In a hearing of MPs, he admitted he could not deny the controversy was a "humiliating shambles for the company".
The group's reputation has been left in tatters and it will lose up to £50 million on the £284 million contract. The hit represents 10 per cent of the firm's annual £500 million profit.
Speaking after a visit to the Olympic Park with Tory MP Mark Reckless yesterday, Keith Vaz, the Labour chairman of the Commons home affairs select committee, said: "I was impressed by the security at the site and want to pay tribute to the work of the police and the army.
"The army presence was particularly visible and they have proved to be a real asset to the Olympic security operation.
"The security queues were short and we were very interested to note that it took longer to get a hamburger from McDonalds than to get into the Olympic park.
"I commend the efforts of everybody involved in making the operation such a success."