Craig Reedie, one of the architects of London 2012's successful bid for the Olympics, said Thursday that the security threat in the British capital was more significant than at most previous Games.

"There are very few people who can remember the last time a Games was held in a city where there is a (terror threat alert)," the former chairman of the British Olympic Association said.

"So the threat here in London is more notable than in previous Games. And the country is taking it seriously."

Reedie believes that despite the fiasco over the failure of private security contractor G4S to provide the number of security guards it had promised, the London Games now has a better chance of being conducted safely.

"The government decided some months ago that it wanted more security guards," said Reedie, who is an International Olympic Committee executive board member.

Even though some of those guards have had to be replaced by 3,500 troops, with another 2,000 possibly to join them, the government's decision in December meant that the security operation was substantially beefed-up, he said.

"I think it will be a good thing, because the Games will be secure," Reedie added.

AFP