The Garda Ombudsman Commission (GSOC) confirmed it cleared Garda sergeant Michael Galvin of any wrongdoing less than 24 hours before his death.
Kieran Fitzgerald, of GSOC, was interviewed on RTE's 'Morning Ireland' programme earlier today where he described the sergeant's death as "tragic" but defended their decision to not inform him that he had been cleared following a GSOC investigation into a fatal road accident in January.
Sgt Galvin took his own life at Ballyshannon Garda Station in Co Donegal 28 May.
In a letter that was addressed to his wife Collette and found by colleagues after his death, Sgt Galvin explained that he could not take the pressure of the GSOC investigation which had left him feeling like a criminal.
Defending GSOC's actions, Mr Fitzgerald said: "Only on the day before his death, did we finally conclude what our finding would be, and it would not normal practice at all to inform people that a file was being considered to be sent to the DPP.
"We’re only discussing this now because it has been referred to publicly. In the normal run of the events, we would not be communicating with people.
“We concluded our investigation, last Wednesday in fact, and it is our feeling and finding that there was no evidence to support the case against Sgt Galvin.
“The original matter we were investigating, and people shouldn’t lose sight of this, was the death of a young lady on New Years in Donegal.”
The woman died following a fatal road accident.
Sources close to the family have said that Collette Galvin is "beside herself" with grief and can not understand why her husband had not been informed by GSOC that he had been cleared of any wrongdoing.
Sgt Galvin's angry colleagues are demanding a High Court judge probe how GSOC conducts investigations, but GSOC is adamant it is investigating the death.
Speaking on RTE's Morning Ireland, Mr Fitzgerald said the sergeant's death had been referred to GSOC by the Garda Commissioner last week.
He said that on May 27 the watchdog had concluded its investigation into the allegations concerning Sgt Galvin and had found no evidence to support wrongdoing.
He said that an external body will review the ongoing inquiry, and that it will also examine the Ombudsman's investigation into the fatal traffic incident on 1 January, which occurred at Ballyshannon- during which Sgt Galvin was interviewed, along with two other gardai.
He said the death of Sgt Galvin “did not call for a High Court judge to investigate.”
“There are provisions under the law for that to happen but I don’t think that this particular circumstance meets that required.
Adding: “Our interactions with Sgt Galvin was appropriate and proportionate… [and] it is not our call to appointment High Court judges.
“While we greatly regret that this tragic death has occurred, I do think it is appropriate we investigate. These are two separate investigations.”