The security firm G4S has apologised and admitted it underestimated the job of recruiting Olympic staff.
A video posted online apparently shows military equipment, being used as part of Olympics security, left unguarded outside London flats.
Fears over security at London 2012 grow.
Police have cordoned off part of a car park at Gatwick Airport after suspicions were raised about a vehicle parked there.
Officers were unable to locate the driver of the Renault van or to view all of the interior of the vehicle. As a result an explosive ordnance disposal unit has been requested to attend the scene.
Inspector Gary Medland from Gatwick Police said: "We are aware that this is likely to cause significant disruption to people arriving or departing NorthTerminal by car, especially at this time of day.
"However, it is important that we establish whether this vehicle poses any threat and the cordon has been put in place for the safety of everyone visiting and working at the airport.
"There is no suggestion that there are any other threats to the airport and both police and security staff are actively checking all areas.
"However, as always, everyone should be aware of security and if they see anything suspicious they should report it to police officers or airport staff or dial 999 immediately."
A committee of MPs has said security firm G4S should drop its £57 million fee after it failed to provide enough staff for the Olympics.
The firm has also been told it should compensate people who were expecting to work during the Games but were not given shifts.
Committee chairman Keith Vaz said the company should pay for what he described as its reckless attitude. Neil Connery has the details
An additional 1,200 troops that were put on standby for the Olympics last week will be deployed, Culture Secretary Jeremy Hunt said today.
A report in The Guardian today has raised fresh doubts on Olympic security being run by G4S, with claims recruits are being insufficiently prepared to detect bombs and other weapons.
Read more on the ITV national news website.
The Metropolitan Police force is to open its Special Operations control room for the Olympic Games later. The centre in Lambeth features the latest in security technology and closed circuit television.
The company providing security for the London Olympics has apologised for not providing enough security staff and says it will pay for extra troops to police the Games. G4S stands to lose up to £50m after failing to meet its commitments. Glen Goodman reports.
Shadow Olympics Minister Tessa Jowell said that Olympic security has not been jeopardised by the failure of G4S to recruit enough security staff. However, she added that questions need to be answered.