Lord Coe, chairman of the organizing committee, said reinforcing the 17,000 troops already assigned to the games might be necessary.
"We are working on that at the moment," Coe said Friday with the opening ceremony just two weeks away.
The Daily Telegraph said another 3,500 service members were dispatched to London earlier this week after a private security contractor came up short in its manpower requirements. Company officials admitted they ran into trouble finding enough qualified applicants.
Although the contractor, GS4, will remain on the job despite the short staff, the British military has contingency plans in place to send more people to the Olympics, The Daily Telegraph said.