The female police officer who was arrested over alleged media leaks about the "plebgate" affair was present at Downing Street during the time of the incident in September, the Metropolitan Police said.
A 46-year-old female police officer from Scotland Yard's Diplomatic Protection Group was arrested over alleged leaks to the media linked to the Andrew Mitchell "plebgate" affair, the Metropolitan Police said.
A 46-year-old male officer arrested yesterday has been bailed to return on a date in March.
David Cameron said it was "very important" the investigation into the 'plebgate' affair was "thoroughly carried out and proper answers are delivered".
The Metropolitan Police said the allegations against the officer arrested today are "extremely serious" and the investigation continues with "urgency, determination and an open mind."
The latest information from Scotland Yard reveals there are now six officers and one civilian arrested or being investigated over the Andrew Mitchell "plebgate" incident.
The man arrested over alleged leaks to the media linked to the "plebgate" affair was not one of the officers at Downing Street during the incident in September 2012, the Metropolitan Police said in a statement.
A police officer responsible for protecting Government officials has been arrested over alleged leaks to the media about the "plebgate" incident.
The 46-year-old from the Diplomatic Protection Group was held at his work place in central London on suspicion of misconduct in public office.
Public confidence in the police force has been shaken because of a "dangerous cocktail" including the "plebgate" affair and the results of the Hillsborough Inquiry, a senior Labour backbencher has said.
Keith Vaz MP, chair of the Home Affairs Select Committee, which will start an inquiry into police accountability, integrity, internal corruption and malpractice in January, said it is a "defining moment" for the service.
He called on Prime Minister David Cameron to host annual summits with senior officers and called for "a new Magna Carta" for policing.
In the Sunday Express, Mr Vaz said recent events had dented the public's confidence in the police.
Met Commissioner breaks off Xmas holiday citing concerns about welfare of 'plebgate' officers as a paper apparently identifies one.
The Met Police (MPS) now has 30 detectives investigating Plebgate with "numerous lines of inquiry" into what happened in Downing St three months ago.
The force has revealed the scope of its inquiry:
- Identify the source of the information to The Sun and The Telegraph newspapers and whether this emanated from the MPS.
- If the source of information did emanate from the MPS, to establish who leaked it and how it was done.
- Alternatively, if the source of the leak was via a third party, establish who that was and how it was done.
- To investigate the circumstances surrounding the Police Officer's claim to have witnessed the incident in Downing Street.
- To establish if there is any evidence of a conspiracy between this officer and any other person.
- Establish what, if any, criminal or misconduct offences are apparent.
- Establish if there is any organisational learning as a result of this investigation.
- 19 September - Andrew Mitchell has an altercation with police officers after they refuse to let him ride his bike out of the main gates of Downing Street.
- 21 September - The Sun reports that Mr Mitchell called the officer "f*****g plebs".
- 24 September - The Sun reports further details citing the official police report. The Daily Telegraph publishes the police log in full.
- 12 October - Mr Mitchell meets members of the Police Federation but fails to win them over.
- 19 October - Mr Mitchell resigns saying his position as Chief Whip had become untenable.
- 15 December - A police constable with the diplomatic protection group, who was not involved in the original incident, arrested on suspicion of misconduct.