LONDON-- Thousands of British soldiers are likely to be posted at Olympic venues after a security review for the 2012 London Games showed that authorities may need to double the number of guards at stadiums and other Olympic sites.

Discussions with the Ministry of Defense are under way after studies suggested that the 10,000 security guards contracted for the games would not be enough. Some 6,000 soldiers are being considered to protect the games, a government official familiar with the plans said Friday.

"The planning was done a few years ago," said the official while speaking on condition of anonymity because of the sensitivity of the information. But the official said the threat had been "underestimated" when it came to looking at the "devil of the detail."

Britain's Home Office issued a statement saying that the government, the Olympic organizing committee and the security company, G4S, were working together to finalize security arrangements and make "the best and most appropriate use of available resources."

British authorities had already planned to have the country's military help secure the games. However, this role was to be limited to certain specialized events, such as patrolling the perimeter of the sailing venue at Weymouth.

But large numbers of soldiers being considered to help out at the venues suggests that Olympics officials will be taking every precaution possible. It is unusual, though not unheard of, to ask the U.K. military to take part in civilian tasks.

However, bringing in soldiers would not necessarily be free of extra costs. The Financial Times reported that Britain's military, which has been hard hit by budget cuts and a dramatic austerity program, wants any use of troops to be paid from games funds.

The 600 million-pound ($965 million) Olympics security budget has been protected from spending cuts and won't be affected by the tough measures aimed at reducing Britain's budget deficit. But the potential of doubling the security force raises questions about where the money will come from to pay the additional personnel.

Security for the Olympics has been a critical -- and costly -- issue for the games ever since the slaying of 11 Israeli athletes and coaches at the 1972 Summer Games in Munich. The London Games are seen as a high security threat as the Olympics offer a ready platform for any terror group intent on wreaking havoc at events broadcast live worldwide.

London and its Olympics have already been hit by terrorism. Homegrown suicide bombers attacked London's transit network in 2005, killing 52 commuters the day after London was awarded the 2012 Olympic games.

The British government is planning for the national terror threat to be "severe" during the Olympics, meaning an attempted attack is highly likely.

Two of the major security contracts have been awarded to G4S, a global security company providing everything from security personnel to monitoring systems, and Rapiscan Systems, headquartered in Torrance, California, which will be providing security equipment and other scanning systems.

About 12,000 police officers will be on duty each day of the July 27-Aug. 12 games.