A police officer is arrested on suspicion of misconduct in public office over the leak of information about the row between former chief whip Andrew Mitchell and officers in Downing Street.

A police officer is arrested on suspicion of misconduct in public office over the leak of information about the row between former chief whip Andrew Mitchell and officers in Downing Street (Reuters)

A constable in the diplomatic protection group was held on Saturday evening and bailed yesterday, Scotland Yard said. He has been suspended from duty.

Mr Mitchell resigned in October after weeks of controversy over what he was reported to have said to police after being told he could not ride his bike through the main gates in Downing Street.

He was accused of using the word "pleb" during a confrontation with officers, which he denied. But in a resignation letter to David Cameron, he admitted swearing.

The story first appeared in the Sun and transcripts of what was allegedly said were published in the Daily Telegraph.

The officer arrested was not on duty at the time of the incident in Downing Street. Metropolitan police statement

Scotland Yard said that on Thursday the Metropolitan police received fresh information regarding the alleged unauthorised disclosure of information.

The matter will be formally referred to the Independent Police Complaints Commission today.

Scotland Yard said in a statement that its own inquiries had not found any evidence that the officers working in Downing Street on the day of the row had been involved in the "unauthorised release of information".

The statement added: "The officer arrested was not on duty at the time of the incident in Downing Street."

In his resignation statement, a month after the incident, Mr Mitchell said it was not fair to put his colleagues and family through such "damaging" stories any longer.

He did not attend the Conservative conference in Birmingham, neighbouring his Sutton Coldfield constituency, after admitting his presence would be a distraction.

He failed to win over Police Federation members by meeting them in his constituency and trying to explain his actions.

He told Mr Cameron: "I have made clear to you - and I give you my categorical assurance again - that I did not, never have, and never would call a police officer a 'pleb' or a 'moron' or used any of the other pejorative descriptions attributed to me."

But he accepted it was "obviously wrong of me to use such bad language and I am very sorry about it and grateful to the police officer for accepting my apology".