'Plebgate': Met Police make third arrest
Metropolitan Police detectives have arrested a police constable as part of the Andrew Mitchell "plebgate" inquiry.
The 46-year-old man was arrested on suspicion of misconduct in a public office and the unauthorised disclosure of information to the media.
Mr Mitchell quit as government chief whip after it was alleged he called Downing Street police "plebs", a claim he has always denied.
CCTV footage has cast doubt on the original police accounts of the row.
The arrested officer was part of Scotland Yard's diplomatic protection group and was not present during the incident at the Downing Street gates in September last year.
He was arrested at his London workplace by officers from the directorate of professional standards and is currently in custody at a central London police station.
In a statement, the Met said: "The allegations in relation to this matter are extremely serious and it is therefore vital that a thorough and proportionate investigation is carried out.
"The investigation continues to be progressed with urgency, determination and an open mind."
The Independent Police Complaints Commission (IPCC) have been informed. They are supervising the Met's investigation into the 'plebgate' row.
While former chief whip Mr Mitchell admits swearing after a police officer refused to let him exit through the main Downing Street gate with his bicycle, he denies directly swearing at the officer and insists he did not lose his temper or call him a "pleb".
The arrest is the third as part of the investigation into the affair, entitled Operation Alice.
On 15 December, a 52-year-old police constable from the same police group was arrested on "suspicion of misconduct in public office".
He was rebailed to return in February 2013 and is suspended from duty.
A 23-year-old man, who is not a member of the police force, was arrested on 19 December suspected of "intentionally encouraging or assisting the commission of an indictable offence", relating to misconduct in a public office.
He was also rebailed to return in February 2013.