An officer has been arrested for allegedly leaking the police log describing the "plebgate" affair which led to the resignation of the Government's chief whip, Andrew Mitchell.
The constable, who serves in the Diplomatic Protection Group, has been suspended after being detained on suspicion of misconduct in public office on Saturday evening and bailed yesterday. He will return for more questioning next month.
Mr Mitchell resigned in October with his career in tatters after contradicting an official police account of a tirade he launched against a police officer, who had refused to allow him to exit the main gates of Downing Street on his bicycle.
Mr Mitchell apologised for his conduct but denied insulting the officer with the politically charged word "pleb", only to be publicly contradicted when the police account was leaked to the press. His implication that the officers in question had lied or were wrong eventually led him to resign.
The Metropolitan Police said last night that the officer under investigation was not among those on duty during the incident, and there is no evidence suggesting any of those who were on duty had any involvement in the information being released.