The watchdog said investigations had been launched into evidence given by officers following the death of Pc Ian Terry, killed in a botched training exercise by Greater Manchester Police (GMP) in 2008, and at a public inquiry into the death of Anthony Grainger, an unarmed man who was shot by a GMP firearms officer in 2012.
The IPCC is also re-investigating the death of 23-year-old Jordan Begley - who was Tasered by GMP officers in 2013.
No officers have ever faced criminal charges over the death of Mr Terry, a father-of-two, although an inquest in 2010 found he was unlawfully killed.
Two officers were found guilty of gross misconduct at internal disciplinary hearings, while a third retired before proceedings could be held.
An IPCC spokesman said a new investigation had been launched into the actions of officers following Mr Terry’s death and the evidence they provided.
He said: “Some of the allegations are still being assessed at this time to determine whether or not they warrant investigation.
“However, the IPCC has commenced an investigation looking at evidence given by a number of officers to the IPCC, to the inquest after Pc Terry’s death, and to the subsequent Health and Safety Executive (HSE) crown court trial.”
A public inquiry into the death of Mr Grainger, 36, from Bolton, began in January this year and has heard officers relied on out-of-date intelligence and inaccurate briefings.
The father-of-two was shot by a firearms officer through the windscreen of a stolen Audi in a car park in Culcheth, Cheshire, on March 3 2012.
The IPCC has said it will consider publishing a report of its investigation into the circumstances of his death once the inquiry has concluded.
The spokesman said: “We have also begun a separate independent investigation into a complaint we received that relates to the evidence given at the public inquiry.”
A report into the death of Mr Begley, who was Tasered and restrained when police were called to his home in Gorton, Manchester, during a row with neighbours, is expected to be published later this year.
The original IPCC report into his death, which found no individual officer had a case to answer, was quashed by the High Court last year after it was found to be inconsistent with the subsequent inquest.
The spokesman said: “The reinvestigation, being led by the IPCC’s Chief Operating Officer Ian Todd, began in early February this year.
“The IPCC investigators have now reviewed all the evidence from the original case, which has then been assessed against evidence given during the inquest.
“The IPCC has not found, at this time, any evidence which would require the GMP officers involved to be re-interviewed by the IPCC.
“This aspect of the investigation remains under review.”