The Metropolitan Police was forced to admit today that one of its senior commanders gave false information to MPs when he denied plain-clothes officers were in the crowd at the G20 demonstrations in London in 2009.
Giving evidence to the House of Commons Home Affairs Committee a month after the protest, in which thousands of demonstrators clashed with police, Commander Bob Broadhurst insisted there were no plain-clothes officers among the crowd.
But the committee's chairman, Keith Vaz, last week wrote to the Met's Commissioner Sir Paul Stephenson after questions arose about Mr Broadhurst's evidence in the wake of the unmasking of the undercover policeman Mark Kennedy, who attended many demonstrations during seven years living as a spy among green activists.
Today, the Metropolitan Police issued a statement correcting the testimony given by Mr Broadhurst in May 2009. He told MPs then: "We had no plain-clothes officers deployed within the crowd. It would have been dangerous for them to put plain-clothes officers in a crowd like that."
But today's statement conceded: "Having made thorough checks... we have now established that covert officers were deployed during the G20 protests. Therefore the information that was given by Commander Bob Broadhurst to the Home Affairs Select Committee saying that 'We had no plain-clothes officers deployed within the crowd' was not accurate."
However, the Met stood by Sir Paul's assurance to the committee at the same hearing that the force did not use agents provocateurs at the protests around the world leaders' summit in April 2009.