A British government oversight committee expressed doubt Friday on whether the 2012 London Olympics can stay within budget in light of the staggering security costs, says an article by the Associated Press.

Security is taking up a large chunk of the 9.3 billion pound budget ($14.6 billion), with planned costs exceeding $1.6 billion.

“We are particularly concerned about the significant increases in the security bill, said Margaret Hodge, chair of the Public Accounts Committee, in a statement. The organizing committee “now needs more than twice the number of security guards it originally estimated and the costs have roughly doubled. It is staggering that the original estimates were so wrong.”

The threat of terrorism at the Olympics is driving the cost of security higher and higher. The British government is planning to identify the national terror threat at “severe” during the July 27 - August 12 event, meaning that an attempted attack is highly likely, according to AP.

Initial security reviews put the number of security guards needed at 10,000, but the security workforce is now at 23,700, along with thousands of soldiers and 12,000 police officers on duty, the article says. An additional $862 million was required to secure venues such as hotels.

 If the costs of security continue to climb past the budgeted amount, the AP reports, Olympic officials would be forced to turn to already struggling taxpayers to balance the amount.