Justice Minister Charlie Flanagan has insisted "there is no conspiracy, no cover-up" surrounding the death of Shane O'Farrell amid ongoing concerns over the terms of reference of the inquiry into the case.
Mr Flanagan rejected any suggestion of issues in how Mr O'Farrell's death is being examined during a Dáil debate with an opposition TD.
Mr O'Farrell was killed in 2011 when he was injured in a hit and run incident while cycling near his home in Carrickmacross, Co Monaghan.
The 23-year-old was hit by driver Zigimantas Gridziuska, who had a string of convictions and was out on bail at the time of the incident.
While the Garda Siochana Ombudsman found no evidence of criminal misconduct by gardaí, since Mr O'Farrell's death, his family have sought a full public inquiry into what happened and how Mr Gridziuska was still driving on Irish roads in 2011.
Both the Dáil and Seanad have voted in favour of the Government setting up a full public inquiry into the circumstances before and after Mr O Farrell's death.
Fianna Fáil TD John McGuinness - who has repeatedly highlighted the case - urged Justice Minister Charlie Flanagan to listen to the O'Farrell family's concerns and those of TDs and senators.
Responding to the demand, Mr Flanagan said it is ultimately up to the judge examining the terms of reference of the inquiry to decide what, if any, changes to make in response to the O'Farrell family's calls for a wider investigation.
However, in an unusual remark which was not part of his scripted statement, Mr Flanagan began his response by saying: "I want to make it very clear, there's no conspiracy here, there's no cover-up here. I want to uncover the facts as much as any deputy in this House.
"There is absolutely no impediment or obstacle to Judge Haughton making any recommendation [about expanding the inquiry or changing its terms of reference]," the Justice Minister said.
The remark was immediately questioned by Mr McGuinness, who told Mr Flanagan: "I'm confused by the reply given, I did not mention a conspiracy or a cover-up."
Mr McGuinness added that the O'Farrell family believes the inquiry terms of reference must be widened, saying not acting on this request means Shane O'Farrell's rights are being ignored.