Three officers accused of giving misleading evidence over the "plebgate" scandal will have to face a fresh inquiry and could face contempt of parliament charges if they refuse to apologise to MPs.
The new probe comes after a scathing report by the Commons home affairs select committee (Hasc) accused the trio of "obstructing the truth" when they initially appeared before the committee.
Police Federation representatives Inspector Ken MacKaill, Detective Sergeant Stuart Hinton and Sergeant Chris Jones were all told they would face no action for misconduct over press statements they made following a meeting with former chief whip Andrew Mitchell in the West Midlands in October last year.
The meeting was in response to an alleged-foul mouthed confrontation Mr Mitchell had with police in Downing Street the previous month where it was claimed he referred to the officers as "plebs".
But the Independent Police Complaints Commission (IPCC) today announced it would hold its own investigation into the officers' behaviour after finding "procedural irregularities" in the way the initial inquiry was dealt with.
Sgt Jones and Det Sgt Hinton have also been called to appear before the HASC for a second time on Tuesday, after being accused of giving "misleading" answers to MPs on October 23. The committee wants the pair "to apologise for misleading it" or face disciplinary action.
The committee's report said the officers' evidence was "possibly deliberately" misleading, lacked credibility and was contradictory.
It also hit out at their refusal to apologise for the actions, given the effect it had on Mr Mitchell's personal life and career. He resigned a month after the altercation took place at the Downing Street gates.
"If evidence was given in a similar manner by three serving police officers to a court of law it is our view that such testimony would undermine a case and lead a jury to reach an unfavourable conclusion as to the credibility of the evidence given by those police officers," the report read.
It was also particularly critical of Det Sgt Hinton for referring to Home Secretary Theresa May as "that woman" before claiming he was misquoted in an apparent attempt to avoid disciplinary action.
"All evidence given to select committees should be provided honestly and not be affected by forethoughts of any future outcome," it said.
"It is an indictment of the quality of evidence provided by DS Hinton that, when specifically asked if the reference to 'this woman that the Conservative Party have' was about the Home Secretary, he suggested that it was 'a typo, to be perfectly honest'."
The report also targeted three chief constables from Warwickshire, West Mercia and West Midlands police, who were said to have shown "an absence of leadership" while the three representatives from their forces were embroiled in the affair.
It went further to mention "extremely serious" suggestions West Midlands Police Assistant Chief Constable Gary Cann put pressure on police to release details of its initial police investigation and findings before it had been signed off by the IPCC.
The committee said if Mr Cann did try to change the report's conclusions before the IPCC received it, it was "both unacceptable and unlawful".
But West Midlands Chief Constable Chris Sims rejected the notion.
"This is a serious inference to draw and I completely refute it," he said.
"I have today written to (Hasc chairman) Keith Vaz MP to ask him to look again at this erroneous conclusion as a matter of urgency."
Although the trio were told they would not face disciplinary action, IPCC deputy chairwoman Deborah Glass said there were "procedural irregularities" between the production of the draft and final West Mercia reports that warranted further investigation.
The report was missing Chief Inspector Jerry Reakes-William's opinion, she said.
Mr Reakes-Williams found the officers had a misconduct case to answer, but his opinion was not included in the report because he mistakenly believed the report should reflect the views of each of the forces' senior officers, Ms Glass said.
"Therefore, for the purposes of the legislation, I consider that in fact there is no final report," she said.
"Consequently, the investigation is not complete and the decision-making function of the appropriate authorities concerning whether the officers have a case to answer for misconduct is not yet engaged; the decisions they have purported to reach are void."
Ms Glass said the IPCC would conduct the investigation itself so public confidence was not eroded further and no-one involved in the first probe would take part in the second.
Mr Vaz said the committee was "appalled" with the officers' evidence.
He said the chief constables also played their part to damage the reputations of the police officers, the Police Federation and the force itself by failing to redetermine their conclusions in the investigation.
Mr Vaz said it was now up to the IPCC to make an independent decision.
"The narrative of what we have seen could rival any great work of fiction," he said.
"At every point and at every level, instead of being transparent, we have uncovered a process that obstructs the truth. If this can happen to a Cabinet minister, what hope is there for anyone else?"
Shadow home secretary Yvette Cooper said the committee's "serious and troubling" report warranted an overhaul of police accountability standards.
" Andrew Mitchell has already waited too long for the result of these investigations and these events are casting a long shadow over the vital and much valued work police officers do across the country," she said.
Former shadow home secretary David Davis said it was worrying the decision of the three chief constables to judge there was no case of gross misconduct had had to be overturned by the IPCC.
He told Murnaghan on Sky News: "This is really worrying because it's not just about the issue of three policemen. It's about whether or not this sort of behaviour is seen as acceptable by the entire system and it looks as though with these three forces they thought it was acceptable.And frankly that's not just good enough for the British public."
The Conservative MP also insisted former chief whip Mr Mitchell should return to the Cabinet in the next reshuffle.
Alex Marshall, chief executive of the College of Policing, also told Sky News he was pleased an independent investigation would take place.
Mr Marshall, the former chief constable of Hampshire Police, said: "This is a damaging episode. This damages trust and confidence in the police service and actually it detracts from the very good work done by officers day and night keeping the public safe and reducing crime, which is what has been happening over recent years."