The State is set to fully defend a High Court challenge brought by convicted murderer Malcolm Macarthur against his continuing imprisonment.
Macarthur was jailed for life in 1982 for the murder of nurse Bridie Gargan in the Phoenix Park. The State withdrew charges against him in relation to a second murder of Co Offaly farmer Donal Dunne.
Macarthur's arrest in the home of the then attorney general embroiled the administration of Charles Haughey in a major political controversy.
Macarthur is now in his 24th year of imprisonment, and is one the longest-serving prisoners in the State.
In 2004 he initiated legal proceedings to have the courts direct the Government to order his release in line with a recommendation of the parole board.
Two years earlier the parole board had recommended that Macarthur should be moved to Shelton Abbey open prison to assess his suitability to be released. This recommendation was perceived as a prelude to his eventual release.
Macarthur was moved to Shelton Abbey in 2004. However the Government has not acted in relation to his release, although he was allowed out of prison for a short period last Christmas.
The State is to file a defence to the challenge brought by Macarthur within the next fortnight, and highly-placed sources said the case would be fully defended.
The Irish Times understands that the State will argue that under the Criminal Justice Act 2003 a recommendation from the parole board is only one element considered by the Minister for Justice in determining whether a prisoner should be released.
Lawyers for Macarthur are expected to argue that it is a violation of their client's human rights for a Minister rather than a court to take a decision on whether he should be released.
Any political decision on whether Macarthur should be released will be taken by the Minister for Defence Willie O'Dea. Minister for Justice Michael McDowell has stepped back from the case as he had acted as a barrister for the defence team in the original trial in 1982.
The Macarthur affair lead to one of the biggest political controversies in the 1980s.
The then taoiseach Charles Haughey described the events of the case as "grotesque, unbelievable, bizarre and unprecedented, which lead Conor Cruise O'Brien to coin the acronym "GUBU" for the government. Macarthur pleaded guilty to the murder of Ms Gargan (27) as she was sunbathing in the Phoenix Park in July 1982.
It appeared that Macarthur had sought to steal her car. Three days later farmer Donal Dunne, who had advertised a shotgun for sale, was murdered in Co Offaly.
Macarthur was acquainted with Patrick Connolly, the then attorney general.
He arrived unannounced at Mr Connolly's apartment in Dalkey several days after the murders and was invited to stay. The following week, gardaí, acting on information about the suspicious behaviour of a man wearing heavy clothes ill-suited to the weather, put the attorney general's apartment under surveillance. They moved in after they saw Macarthur look out the window.
Macarthur's trial also generated huge controversy. After he pleaded guilty to the murder of Ms Gargan and received the mandatory life sentence, the DPP withdrew charges in relation to the murder of Mr Dunne. A petition seeking his trial for the murder of Mr Dunne was unsuccessful.