They will also be called back before an influential committee of MPs over evidence they gave to them previously.
The Independent Police Complaints Commission said there were "procedural irregularities" in an earlier probe.
The three Police Federation reps had been told they would face no action over the so-called Plebgate affair.
In September 2012, Mr Mitchell was accused of calling Downing Street officers "plebs" after they refused to let him ride his bicycle through the main gates.
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Evidence given to the Home Affairs Select Committee on October 23 revealed a number of procedural irregularities between the production of the draft and final West Mercia reports”
IPCC deputy chairwoman
The then cabinet member apologised for using bad language but denied using the word pleb. He later resigned as chief whip as the row continued.
A month later, Mr Mitchell held a meeting in his Sutton Coldfield constituency with Det Sgt Stuart Hinton, Insp Ken MacKaill and Sgt Chris Jones from the federation in an attempt to smooth things over.
After the meeting the officers, who represent rank and file officers in Warwickshire, West Mercia and West Midlands respectively, briefed the media.
A transcript of a recording Mr Mitchell made of the meeting contradicted the officers' account of what was said.
Ch Insp Jerry Reakes-Williams, head of professional standards at Warwickshire and West Mercia Police, carried out an investigation and concluded they had a case to answer for misconduct, but their senior officers disagreed.
Now the Independent Police Complaints Commission (IPCC) has announced it will conduct its own investigation into the officers' behaviour.
Det Sgt Hinton and Sgt Jones have additionally been called to reappear before the Home Affairs Select Committee after being accused of giving "misleading" answers to MPs last month. The committee wants them "to apologise for misleading it".
IPCC deputy chairwoman Deborah Glass said: "Evidence given to the Home Affairs Select Committee on October 23 revealed a number of procedural irregularities between the production of the draft and final West Mercia reports.
Andrew Mitchell arriving at Downing Street on his bicycle
A confrontation between Mr Mitchell and police sparked the "plebgate" saga
"On August 12 2013, a final report was provided to the IPCC. It contained a single set of conclusions to the effect that no case to answer for misconduct was made out against any of the three officers under investigation.
"However, it is clear from CI Reakes-Williams's evidence to the Home Affairs Select Committee that this conclusion did not reflect his opinion. His opinion was (and remains) that a case to answer for misconduct was made out.
"However, he mistakenly believed that his report should reflect the view of the 'appropriate authorities' - the senior officers in each of the forces involved.
"The 'appropriate authorities' are the final decision-making bodies, and they are entitled to reach a different decision to the conclusions of the investigator.
"However, this is an entirely separate process. The procedure described above has conflated the two."
Ms Glass said she did not have the power to reopen the investigation when she gave evidence to MPs on the same day as the officers.
Home affairs committee chairman Keith Vaz: "The reputation of our great police service can be restored"
But she has now said the investigation was incomplete because the final report did not include Ch Insp Reakes-Williams' opinion.