The money will make venues more blast resilient, the goverment said
A £19m cash injection has been approved by ministers to strengthen London's Olympic Park venues against the threat of a terrorist attack.
The money will make the venues more blast resilient, the Department for Culture, Media and Sport (DCMS) said.
The credit crunch has forced organisers to dip into the contingency fund, of which £1.272bn remains from the £1.972bn available.
The overall funding package for the 2012 Games is £9.325bn.
A spokesman for the Olympic Delivery Authority (ODA), which is in charge of delivering the 2012 project, said: "The forecast for security has not increased as this cost was included in the anticipated final cost in the previous report."
The contingency fund is used to cover risks outside of the control of the ODA.
Olympic Minister Tessa Jowell said "good progress" was being made on the Olympic Park in Stratford, east London.