The police investigation in to the "Plebgate" affair which led to the resignation of former chief whip Andrew Mitchell has cost nearly £150,000, it emerged.
Codenamed Operation Alice, the Scotland Yard inquiry was launched after claims that officers may have lied about the dispute with Mr Mitchell when they refused to let him leave Downing Street on his bike via the main gate in September last year.
In a letter from Deputy Assistant Commissioner Patricia Gallan, leading the investigation, to Keith Vaz, chairman of the Commons Home Affairs Select Committee, it was disclosed the cost of the police investigation had reached £144,000.
DAC Gallan wrote: "It remains that I have 30 officers at my disposal and the Operation Alice is estimated to have cost £144,000 to date."
"Four people have been arrested and no individual is currently charged. The advice file submitted to the CPS by the MPS (Metropolitan Police Service) has specifically asked for advice and guidance surrounding the future of the investigation in relation to potential criminal charges."
Scotland Yard are looking into the possibility of criminal charges in the 'Plebgate' affair.
The inquiry, codenamed 'Operation Alice' began after claims that officers involved in the row may have lied about the dispute with Mr Mitchell, when they refused to let him leave Downing Street on his bike through the main gate in September last year.
At the time it was claimed at the time that Mr Mitchell swore at the officers and called them "plebs". He strenuously denies the allegations, and was forced to resign from his post as David Cameron's Chief Whip after a series of damaging headlines.
Police investigating the 'Plebgate' affair in which Sutton Coldfield MP Andrew Mitchell resigned from his Chief Whip post, are seeking advice from the Crown Prosecution Service on the next step of the investigation.
The police watchdog has replied to former chief whip Andrew Mitchell's letter, where he voiced concerns over the apparent leaking of a report into the 'plebgate' scandal.
In a letter to the Independent Police Complaints Commission, Mr Mitchell said the leaking of information had been "spun" to the officers advantage.
Deputy Chair of the IPCC Deborah Glass has replied:
While this does not rule out the possibility of the MPS file having been leaked, it also raises other possibilities, either that someone who may have been connected to the investigation or in possession of material had a conversation with a reporter, or that the author/s of the articles were reporting speculatively – I note, for example, the references in both stories to “…it is understood that..."
While I fully understand your concerns about these press reports, it appears to me that the public interest is best served by ensuring that the MPS [Met Police] are indeed carrying out a robust and thorough investigation into the initial incident and its aftermath.
Scotland Yard's under increased pressure to allow the police watchdog to investigate the Plebgate affair, after former chief whip Andrew Mitchell issued a formal complaint against the Metropolitan Police.
The MP for Sutton Coldfield and former MP for Gedling quit the Cabinet over claims he called police officers "plebs".
He denies using that word but admits swearing at them for refusing to allow him to ride his bike through the main Downing Street gates.
The Conservative MP is suing The Sun over its reporting of his infamous row with officers in Downing Street as a file investigating police involvement in the incident is passed to prosecutors.
ITV News' Political Correspondent Alex Forrest reports:
The newspaper said it is understood there is nothing in the file to support a claim that Met police officers were involved in an conspiracy to frame the former chief whip.
Andrew Mitchell's lawyers sent The Sun a "letter before action" last month, putting it on notice that the Conservative MP intended to sue.
At the time, his lawyer Graham Atkins told The Guardian: "We are seeking damages, an apology, an undertaking that the words complained of are not repeated, and costs."
The newspaper was the first to break the story of Mr Mitchell's row with the officers at Downing Street, which became known as the "Plebgate" scandal.
The Sun's political editor Tom Newton Dunn has confirmed the newspaper will defend itself against a libel writ from Andrew Mitchell.
Statement issued by The Sun tonight re #plebgate: A Sun spokesman: "We stand by our story and will defend this claim vigorously".