LONDON -- Security checks of vehicles entering Olympic sites in the U.K. have not been properly carried out, according to a number of staff, ITV News reported Wednesday.

The unnamed staff claimed that in some cases fake searches of vehicles for bombs were carried out using dogs that had not been trained to detect explosives. 

The company involved, G4S, denied the claims and ITV News reported that some of the staff who spoke to them had been sacked.

The U.K. news station said the “key claims” were that:

• Cargo areas of trucks and vans have not been adequately searched by either dogs, scanners or other security teams.
• In some instances, dogs that were not trained to find explosives were used to carry out fake searches of vehicles.
• Some assessments of dogs and handlers have been faked.

Read more from ITV News

Ian Horseman Sewell, G4S’s managing director of global events, told ITV News the allegations were not true.

"At no point is there any evidence that dogs that have been trained to detect substances other than explosives have been used to try to detect explosives,” he said.

Olympic rings on London's Tower Bridge mark one month to games

The security operation at the Olympics will be the largest carried out in Britain in peacetime, ITV news said.

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