The Association of Garda Sergeants and Inspectors has called on the Government to appoint a High Court judge to investigate the death of a Garda Sergeant in Co Donegal.
Sergeant Michael Galvin died at Ballyshannon Garda Station last Thursday.
Previously, he had been questioned by GSOC officers as part of an investigation into a fatal traffic incident on 1 January.
The Association's comments follows the news that the Garda Ombudsman Commission is to engage an outside authority to conduct an independent review into two of its investigations following the sudden death of Sgt Galvin.
GSOC is now investigating the death but the external body will review the ongoing inquiry.
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 gardaí.
An internal review by GSOC has found that investigation was "proportionate and reasonable."
The Ombudsman said this morning it had received no complaint about Sgt Galvin but the case had been referred to it by gardaí.
Sgt Galvin was interviewed twice by GSOC, the second time under caution - which the Ombudsman says is procedure - seven days before his death.
The investigation found no evidence of criminal behaviour or a breach of discipline and a file was due to be sent to the Director of Public Prosecutions.
The Ombudsman stressed today that it is the DPP who decides what action is to be taken and that formal letters confirming that the file was being sent to the DPP had been prepared by last Monday and were due to be sent to the three gardaí.
Three days later Sgt Galvin died. He appears to have taken his own life.
GSOC said it has already carried out an internal review of the case and following an examination of the transcripts and interviews it is satisfied the investigation was "proportionate and reasonable."
In a statement this afternoon, GSOC said its investigation "found no evidence of a criminal offence or a breach of discipline by any garda member. It is unusual that GSOC would share its findings at this point in the process, but given these exceptional circumstances we believe that it is appropriate".
Today the Association of Garda Sergeants and Inspectors strongly criticised GSOC for launching a criminal investigation into an anomaly in a statement, made by Sgt Galvin, regarding the fatal traffic incident on 1 January at Ballyshannon.
The Association also said it is unacceptable that GSOC engage an outside authority to review its investigations.