The Labour Party has demanded an explanation from the Government on why "crucial information" was withheld from the Dáil and a coroner when the Morris Tribunal into Garda corruption was established.
The party's justice spokesman, Mr Joe Costello, called for the Minister for Justice, Mr McDowell, to make a full statement explaining why certain information about the death of cattle dealer Richie Barron was not available to TDs when they voted to set up the tribunal in 2002.
Mr Barron was found lying on a road with serious head injuries in Raphoe in October 1996.
It has emerged that the gardaí were initially treating the death as murder, but then re-designated it in the PULSE system in February 2002 to death by dangerous driving.
"This was never revealed to the Dáil, and we need a full explanation as to why that happened," Mr Costello said.
"Secondly, we need a full explanation as to why this information was not made available at the coroner's inquest seven months later."
Det Supt John McGinley told the inquest into Mr Barron's death in September 2002 the case was initially treated as a hit-and-run but changed to an investigation of suspicious circumstances or foul play.
The inquest was not told of the re-designation the previous February.
Mr Costello called on Mr McDowell to clarify what information was in his possession and whether or not the details that have emerged were ever passed to him by the Garda.
"This is an extremely serious matter as it involves all the arrests, charges, and confessions that form part of the investigation into the death of Richie Barron," the Dublin Central TD said. "These details would also have had a major bearing on the outcome of the Tribunal and the original coroner's inquest."
Mr Costello has tabled a Dáil question to the minister seeking a full statement.
Fine Gael's justice spokesman, Mr Jim Higgins, has also called for a statement from the minister. He said the information that the case was not being treated as murder could have changed the nature of the Morris Tribunal's inquiry.
According to the terms of reference of the tribunal, part of its remit is to inquire into "investigations in relation to the death of Mr Richie Barron ... with particular reference to the arrest and treatment of persons in custody in connection with that investigation, the progress, management and effectiveness of the Garda investigation with particular reference to the management of informants."
