Scotland Yard is preparing to launch pre-emptive arrests of individuals plotting to disrupt the Olympic Games.
The head of the force's security operation for London 2012 revealed that it would act if it found intelligence that people were targeting the event.
Assistant Commissioner Chris Allison said the force was prepared to repeat the tactics used before the Notting Hill carnival in west London last summer when dozens of suspected troublemakers and gang members were seized in dawn raids. At the time it described the tactic as "robust".
Allison, in charge of Britain's biggest peacetime policing operation, said: "If we have intelligence that a particular gang is about to do this, then we will take action against them, obviously within the law. Pretty much the same way we do for Notting Hill carnival.
"Each year for the carnival we identify those intending to go to commit crime and where we have evidence of them having committed offences already we take action to prevent them going to carnival to disrupt.
"If we have evidence or intelligence that an individual is intending to or that a person has committed a crime we will take action. That may be before the Games to prevent them disrupting the Games."
Criticism of "pre-crime" arrests was heard in the High Court last week when activists accused the Metropolitan Police of in effect "suppressing anti-monarchist sentiment" during the royal wedding in London last year.
Observer