A group of retired senior gardai has submitted a report to government criticising the findings of the Smithwick Tribunal in an unprecedented challenge to a State tribunal by former members of the force.
The senior officers are questioning the tribunal's conclusion that gardai colluded in the IRA murder of the two RUC officers in South Armagh in 1989.
Chief Superintendents Harry Breen and Bob Buchanan were shot dead by the IRA in south Armagh shortly after leaving a meeting with Gardai in Dundalk Garda Station.
Judge Peter Smithwick concluded that on the "balance of probabilities" there was garda collusion in their deaths – but he was unable to identify possible culprits.
The retired gardai are understood to be deeply unhappy with the judge's findings. They commissioned a lengthy critique of his report and submitted it to the Government this weekend.
Another source said: "There is a feeling that Smithwick went unchallenged. They are putting this out there so that it will be on the record. They want a public debate about it."
The senior gardai are expected to go public with their criticisms once the Government has had a chance to read their submissions. Their protest against the Smithwick inquiry's report reflects growing discontent amongst Gardai, both serving and retired.
The only former member of the gardai to work for the Smithwick Tribunal has also criticised its findings of garda collusion. Gerry O'Carroll, a retired detective inspector, was employed as an investigator for 10 months.
Mr Carroll told the Sunday Independent: "I came to the view there was no evidence of collusion in those murders. "The IRA set up three different ambushes on three different roads, clearly they were unaware of which road those men were taking."
Mr Carroll is not part of the group of retired officers that made the submission.