Lane Clark & Peacock general insurance partner Mark McCausland said the Athens bombings earlier this week were “a massive wakeup call to everyone concerned with the 2004 Games”.

He said it was unlikely that the final wording for the IOC’s cancellation policy, announced last week, had been agreed.

“Given the speed with which this cover has been purchased I consider it unlikely that the formal wording has been thoroughly agreed and a complete policy document issued.

“It is possible that the policy might include a provision that should the risk of a terrorist strike increase significantly during the interim period the insurers could have the right to either increase the premium or possibly restrict the cover in some way.

“It is also unlikely that any premium has to date been paid to the insurers.

McCausland said one option for the IOC in the event of another terror attack before the Games would be to postpone the event, as the financial implications would be less severe than if the Games were cancelled.

He added: “In the event of an a terrorist attack, the Games sponsors may have subrogation rights in the event that assurances relating to security not subsequently being honoured.