British Olympic Association chairman Colin Moynihan admits police and security chiefs can never completely eliminate the threat of “one idiot” disrupting events at London 2012.

Moynihan was speaking after a lone protester forced Saturday’s Boat Race to be halted for half an hour after swimming into the path of the Oxford and Cambridge crews.

Trenton Oldfield, 35, has been charged with a Section Five offence under the Public Order Act and bailed to appear at Feltham Magistrates’ Court on Monday, April 23.

The incident raised immediate concerns about the forthcoming Olympics, where the public will line the route for the marathon, triathlon, road cycling and open water swimming.

Moynihan insists Olympic security, which is being overseen by the Home Office, was under constant review, but that it was difficult to stop individuals.

“It just takes, and is likely to be, one idiot,” Moynihan said.

“It’s not likely to be a well-orchestrated campaign.

“It is likely to be someone similar to the idiot (on Saturday) who causes major disruption.

“That is why all the security measures need to be put in place to minimise the chance of that happening.

“You can never completely remove it, but you can do everything possible to protect the interests of the athletes by minimising it.

“It is so important to work closely with police and security agencies and to put in place every possible measure to protect the interests of all the athletes.

“Every conceivable scenario is being reviewed, and I’m confident no more can be done.

“It’s not impossible, but it is a major challenge.”