Plebgate: Draft report recommended disciplinary action
An internal report that found no misconduct case to answer by police over a meeting with "Plebgate" MP Andrew Mitchell had initially proposed disciplinary action, it has emerged.
The Independent Police Complaints Commission said police chiefs had overruled the recommendation.
Home Affairs committee chairman Keith Vaz has demanded to see both versions.
The prime minister has said police owe Mr Mitchell an apology over the fallout from a row in Downing Street last year.
David Cameron's intervention came as the row deepened between West Mercia, West Midlands and Warwickshire police forces on one side and the Independent Police Complaints Commission (IPCC) and supporters of the former cabinet minister on the other.
Mr Mitchell had been accused of calling police officers "plebs" after being prevented from riding his bicycle through Downing Street's main gates in September 2012.
In an attempt to heal relations with the police he met local representatives of their union, the Police Federation, in his constituency.
Speaking after the meeting, one of the officers, Insp MacKaill, called for the then-Conservative chief whip's resignation, claiming he had not provided a proper account of what happened.
However, Mr Mitchell recorded the meeting and a transcript issued by the IPCC showed he had spoken at length about what happened, and, while he admitted swearing, had denied using the word "pleb" or insulting the police.
A subsequent internal investigation into the officers' account of the meeting initially found there was a "case to answer for misconduct" - but the final version recommended no action be taken against the officers.
The differing conclusions were revealed in a letter from IPCC chairwoman Deborah Glass to Warwickshire's Police and Crime Commissioner Ron Ball.
"It is certainly being portrayed as though it is sinister," Mr Ball told the BBC.
"I think it may be, and I think there may be a perfectly innocent explanation for it... It may simply be that two individuals have looked at it - one has come to one judgement and one has come to another."
He also criticised the IPCC after the watchdog questioned the West Midlands officers' "honesty and integrity".
"I expect the IPCC to behave judiciously and to use judicious language and I don't think they have in this case."
On Tuesday, the watchdog said the officers who attended the private meeting with Mr Mitchell last October should have faced misconduct hearings for misrepresenting what he has said.
The chief constables of West Mercia, Warwickshire and West Midlands forces, who decided not to discipline the officers, will appear before the Home Affairs Select Committee on 23 October.
Mr Vaz has requested that the committee see both the version which recommended disciplinary action and the subsequent one which did not.
"We didn't until today know that there was a first draft which suggested officers may well have been involved in misconduct and a final draft which removed that," he told the BBC.
"We want to be extremely fair to all sides. At the moment we just have the report that has been prepared by the IPCC which is pretty damning."
He added that it was "another twist to a very sorry saga".
IPCC chairwoman Dame Anne Owers, deputy Ms Glass, and Police Federation chairman Steve Williams have also been asked to appear before the select committee.
In a statement on Tuesday, the three chief constables said they welcomed the opportunity to speak.
'Abuse of process'
Earlier at Prime Minister's Questions Mr Cameron said "these things should be properly investigated".
Home Secretary Theresa May has said the IPCC's report "made troubling reading".
Mr Cameron said: "I agree 100% with what the home secretary said. What's being discussed here is the fact that... the former chief whip had a meeting with Police Federation officers in his committee.
"Fortunately this meeting was recorded, so he has been able to prove that what he said was true and what the police officers said was untrue."
The Police Federation of England and Wales has said it was "shocked" by the IPCC's comments, which it said "will naturally undermine the considered findings of the investigation in the eyes of the public".
In a statement it said: "Either the IPCC are capable of supervising investigations or they are not. If they feel that they are capable of doing so... the proper and responsible course must be to accept the investigation findings."
West Midlands Police and Crime Commissioner Bob Jones said comments attributed to Ms Glass in the IPCC statement about the chief constables was "gratuitous and in my opinion an abuse of process".
He said: "I will be writing to the IPCC asking for an apology for what I consider an unwarranted attack on the integrity of the investigating officers and the senior officers who sat in judgement."