Garda Commissioner Martin Callinan has disputed the Smithwick Tribunal's assertion that a culture of prizing loyalty over honesty prevails in the force to this day.
Mr Callinan's defence of the Garda came on a day in which Sinn Féin leader Gerry Adams met with derision across the political spectrum for claiming murdered RUC officers Harry Breen and Bob Buchanan had a "laissez faire" attitude to their own safety.
In his damning report on the killings by the Provisional IRA in 1989, Mr Justice Peter Smithwick said it was still the case that Garda culture prioritised the good name of the force over the protection of those seeking to tell the truth.
This followed his criticism of the failure to fully investigate claims of collusion in the aftermath of the murders.
Mr Callinan accepted the judge's central finding that someone in the Dundalk gardaí colluded with the IRA, and he apologised without reservation to the Breen and Buchanan families.
In his first response to the report, Taoiseach Enda Kenny said in Japan that the findings were "shocking" and a revelation of another dark patch in recent Irish history.
'Beyond comprehension'
Mr Callinan said it was "beyond comprehension" to think that any garda would engage with the IRA at any level. "To betray both themselves and my organisation in such a fashion is beyond belief," he said.
However, Mr Callinan rejected the tribunal’s repeated statement that members of the force place loyalty above honesty. “I have read those comments. I have to say that the police force that is described is not the police force that I lead,” he said.
"Everything we do in An Garda Síochána is designed to establish the truth. An Garda Síochána seeks to establish the truth. That is our raison d'etre and that will continue to be the case."
Minister for Transport Leo Varadkar said on RTÉ television that the Garda leadership must now adopt an approach that seeks to shine a light into any "dark areas".
'Root out the bad apples'
He said he was struck by the tribunal's criticism of gardaí for putting loyalty over trust and reputation over honesty and probity. "I think what has to happen now is the Garda Commissioner in particular needs to make sure that the culture of the gardaí is always to root out the bad apples, and to demand honesty and probity."
Mr Varadkar argued it would be unfair to say Garda culture was not that way currently, but said there had been “a lot of stories” in recent months in relation to problems in the force.
Although Mr Adams faced criticism for suggesting the RUC men seemed to think they were immune from attack by the IRA, Sinn Féin indicated there would be no apology.
Mr Adams has been under political pressure in recent weeks over his denials of any involvement in the killing and secret burial of people “disappeared” by the IRA. He has also faced questions over his failure for many years to report the sexual abuse of his niece by his brother.