"I am disappointed by what seems to be a leak to the press out of what is an ordinary and internal meeting. Such behaviour appears to be contrary to the values of the organisation and this will be looked into accordingly."
Asked on Thursday how much the police operation to remove Brian's signs had cost, Blair came up with the figure of £7,500.
But astonishingly, the following day, when the issue was discussed by the Met's management board, the true figure of £27,754 was divulged. Within hours, details of the meeting were passed to a journalist, who contacted Scotland Yard for a comment.
That afternoon, Sir Ian admitted that he had misled the authority, as the true cost of dismantling the anti-war protester Brian Haw's placards, including officers' pay, was £27,754.
A Scotland Yard spokesman said: "There is an inquiry under way into the coverage of matters discussed at a meeting on May 26."