Theresa May warned that rioters could target 2012 Games

Gangs involved in last month's riots could attempt to disrupt the 2012 London Olympics, Theresa May, the Home Secretary, was told yesterday.

Fears over attempts to disrupt the Games have been privately relayed by a former police officer to the Commons home affairs select committee, which is examining the worse wave of unrest to hit England for 30 years.

MPs on the committee confronted her with the warning from a recently retired officer who served on Operation Trident, the Met's operation against gun crime in the black community. Ms May, appearing before the committee, acknowledged the danger that the gangs could use the Olympics as a catalyst for looting and violence.

She said the team planning Olympic security was examining the riots to see if there were implications for the safe staging of the Games. David Cameron originally blamed gangs for much of the trouble and said he was seeking advice from Bill Bratton, the US police chief, on tackling the problem.

However, Ms May accepted the proportion of gang members involved in the unrest was "not as high as people first thought". But she added: "There is some evidence that obviously there was some gang activity taking place in terms of encouraging people to take part in these events and as we saw, some of that encouragement was being propagated on social media."

She announced she was staging an international conference next month to share ideas for the best way of tackling gang culture. Ms May refused to be drawn on the causes of the sudden outbreak of rioting.