Dorset Police officers are being drafted in to fill the gaps in Olympics security left by under-fire firm G4S.

But they should be able to be withdrawn ‘over the coming days’, G4S has said.

The private firm, which has seen its shares dive by as much as 10 per cent following the Games security debacle, said venue security was being tightened ‘before the full complement of accredited staff have been assigned’.

A G4S spokesman said: “This situation is being rectified over the coming days, which should lead to the withdrawal of police officers from those roles assigned to private security.”

With less than two weeks until the opening ceremony, ministers insisted the Games would be secure and dismissed the firm’s failure to provide the promised 10,000 security guards as a ‘hitch’.

But hundreds of police officers are now being deployed to support security regimes at venues, in addition to the 3,500 servicemen and women who were called in last week.

The forces involved are Dorset, Surrey, Hertfordshire, Northumbria, South Wales, Strathclyde, West Midlands, Thames Valley and Greater Manchester.

Clive Chamberlain, chairman of Dorset Police Federation, said so far the Army has covered for the shortfall in G4S staff.

He said: “On a daily basis it’s a lottery as to how many staff are going to turn up. The best they’ve managed is 15 per cent not turning up, and on the worst occasions they have been 59 per cent down. It’s a fiasco.

“My biggest fear is that G4S are now panic-recruiting to get as many people as they can into the organisation.

“What proper training will they have had before they start? It’s very, very worrying.”

Dorset Police said it would not be not be releasing details of the number of officers drafted in, only that this number will change based on circumstances as they develop.

It added that forces are deciding locally how to find officers to fill the G4S gap.

A Dorset Police spokesman added: “The current deployments will be kept under review and we do not want to provide speculative commentary.”