Number of police officers suspected of conspiring about Andrew Mitchell in 'Plebgate' row rises to 10 The criminal investigation into the 'Plebgate' affair has widened with at least 10 police officers now suspected of involvement in an alleged plot against former cabinet minister Andrew Mitchell. The Independent Police Complaints Commission has extended its supervision to cover the criminal inquiry, codenamed Operation Alice, after receiving fresh information leading to, and emanating from recent arrests. Previously, the IPCC was only supervising the inquiry into circumstances surrounding a police officer's claim that Mitchell branded Downing Street guards 'plebs'. At least 10 police officers are suspected of an involvement in an alleged anti-Tory plot against former cabinet minister Andrew Mitchell, pictured left. He was accused of calling Downing Street guards, pictured right, 'plebs' Only a handful of officers were thought to have played their part in the alleged plot. The inquiry now encompasses officers from four forces: Metropolitan police, West Mercia, West Midlands and Warwickshire. Some have been accused of fabricating allegations about what Mitchell said during the incident or making false statements to the press. Others have been accused of leaking details to the media. According to The Sunday Times, sources close to the inquiry said that Pat Gallan, a Scotland Yard deputy assistant commissioner, in charge of the case, will send her report on the case to the Crown Prosecution Service this week. Keir Starmer, the director of public prosecutions, is expected to make the final decision on criminal charges. Mitchell, who was chief Tory whip at the time, was accused of calling police officers "f****** plebs" in September. It led to Mitchell's resignation one month later. However, he strenuously denied the allegation. The Independent Police Complaints Commission's role in the criminal investigation has grown following fresh information The inquiry now comprises officers from four forces: Metropolitan police, West Mercia, West Midlands and Warwickshire. It emerged two months later that an email suggesting to be a member of the public who spotted the incident was written by an off-duty officer who was not there. Doubts also emerged about a police account of what happened during a meeting between Mitchell and West Midlands Police Federation to discuss the case. The Metropolitan police began an investigation. Three London-based police officers were arrested and are being investigated for misconduct in public office. One has been suspended. Seven Metropolitan police officers, including the three arrested, were handed regulation 15 notices warning them that they were under investigation for professional misconduct. It is thought a relative of one of the officers has also been arrested. Three officers in the Midlands are now being investigated by their own forces. They include Ken Mackaill, chairman of West Mercia Police Federation. The former cabinet minister is understood to have submitted a tape of a secretly-recorded meeting with Mackaill to police. The IPCC said that three senior police federation officers in West Mercia, West Midlands and Warwickshire are facing disciplinary inquiry over remarks made on TV.