Minister for Justice Mr O’Donoghue has described as "mischievous and contemptible" a call for his resignation by Fine Gael’s Mr Jim Higgins.
Mr Higgins made the call in the wake of post mortem results on the exhumed body of a Donegal cattle dealer which raise serious questions about the original Garda inquiry into the man’s death.
A spokesman for Mr O’Donoghue told ireland.com this evening that Mr Higgins was "deliberately exploiting the feelings of the families involved to score cheap political points."
The results of the post mortem show that Mr Ritchie Barron, who died five years ago, was the victim of a hit-and-run incident and not murder as originally assumed by the gardaí.
The circumstances of Mr Barron's death has been surrounded by controversy after allegations that members of the Garda had mishandled the original investigation and were involved in widespread corruption.
Members of a local Raphoe family, the McBrearty's claimed they were subjected to intense harrassment by the gardaí.
Earlier Fine Gael’s Mr Jim Higgins today said he believed the position of the Minister was untenable in light of the findings.
Mr Higgins said: "The disturbing development calls into immediate question the competence of the Minister for Justice. For the past two-and-a-half years, Mr O’Donoghue has presided over a charade of a Garda investigation."
Labour’s Mr Brendan Howlin called again for the immediate publication of the Carty report into alleged Garda corruption in Donegal and said that a full public inquiry could no longer be denied.
Mr Howlin said the Minister should publish this report now or have "the decency to resign."
The Department of Justice claim the Minister is in consultation with the Attorney General to see what form of inquiry can be initiated which will not prejudice the pending civil and criminal cases.