The Attorney General has directed that a new inquest be opened into the death of Mr Seamus Ludlow, a Dundalk man allegedly murdered by loyalists in May 1976.
The family of the 47-year-old forestry worker believes that he was murdered by a gang of four loyalists, two of them members of the Ulster Defence Regiment, and has been campaigning for a full public inquiry into his death.
At the time, it was claimed that the IRA had murdered Mr Ludlow because he was suspected of being an informer, but senior republican sources subsequently denied this.
Mr Ludlow, a bachelor, is believed to have been targeted at random by the gang, who saw him hitching a lift from the outskirts of Dundalk to his home at Thistlecross, about a mile north of the town and close to the main road to the Border.
He was shot and his body was dumped a short distance from his home. No one ever claimed responsibility for his death.
Yesterday the Louth County Coroner, Mr Ronan Maguire, confirmed that he had been directed by the Attorney General, Mr Rory Brady, "to open a completely fresh inquest".
The decision was welcomed yesterday by members of Mr Ludlow's family.
The original inquest was held in Dundalk in August 1976, but none of the family was present, and they understand that no ballistic or forensic evidence was presented.
"We expect this evidence to be heard this time and, unlike the last inquest, we will be present and will have a legal team representing us to ask questions," said Mr James Sharkey, a nephew of the dead man.
Mr Sharkey said that the Police Ombudsman of Northern Ireland, Ms Nuala O'Loan, had told the family earlier this year that two of the bullets used in the murder had been sent to the RUC in the late 1970s, so tests could be carried out to see if these could be linked to the murder of a man in Comber, Co Down, in 1976.
Mr Sharkey said that his family had not known of this until the meeting with Ms O'Loan.
In 1999 the RUC arrested four men on suspicion of being involved in Mr Ludlow's murder. However, the DPP in Northern Ireland decided not to prosecute.
The new inquest into the death of Mr Ludlow is expected to take place in Dundalk before the end of this year.