The Olympic Games could go over the �9.3bn budget unless action is taken to curb costs, the National Audit Office has warned.
It said a doubling in estimated security costs meant there was risk that more taxpayer funding would be needed.
Yesterday, the government revealed an extra �271m was needed for security guards.
But Government ministers say over n �500m remains in unallocated funds for dealing with any further contingencies.
More on this story later.
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