One of Ireland's most notorious killers, Malcom McArthur, has been turned down for temporary release.
His application was rejected by the Minister for State at the Department of Justice, Mr Willie O'Dea, who overturned a Parole Board recommendation.
Mr O'Dea acted in place of the Minister for Justice, Mr McDowell, who had to absent himself from the case because he was a lawyer at McArthur's 1982 murder trial.
McArthur (58) received a life sentence for bludgeoning a young nurse, Bridie Gargan, to death in the Phoenix Park that year. He was also charged with the shooting of a farmer Donal Dunne, who had met him to sell a shotgun.
But the Director of Public Prosecutions, Mr Eamon Barnes, decided not to try him for this offence, prompting 100,000 people nationwide to sign a petition in protest.
Mr McArthur is being held at the Shelton Abbey prison in Co Wicklow. He was moved there last May following a parole board report recommending that he be moved to the open prison to test his suitability for release.
Labour Party Justice spokesman Mr Joe Costello called on Mr O'Dea to explain why he turned down the Parole Board's recommendation for McArthur's temporary release.
"McArthur was involved in horrific crimes but the Parole Board is established to make decisions on people's future. The normal situation would be that you wouldn't expect a minister to influence the decisions."
He said that Mr O'Dea should publish the Parole Board's recommendation in full. Malcolm McArthur was captured by detectives in the summer of 1982 at the apartment of the-then attorney general Patrick Connolly, who was unaware of what he had done.
Mr Connolly handed in his resignation to taoiseach Mr Charlie Haughey, who famously described the events as "grotesque, unbelievable, bizarre and unprecedented".