A 27-year-old Dublin man died today after being found shot near the Border.
The victim was found lying beside another man, who was aged 35, also wounded, near the village of Forkhill, South Armagh.
Police in Armagh confirmed they were liaising with gardaí as part of the murder investigation.
The two men, both from Dublin, were found at the Carrickasticken Road, in the countryside near Forkhill.
The Police Service of Northern Ireland said it was investigating the circumstances of the shooting last night. Assistant Chief Constable Stephen White said: "It's a despicable act."
The man whose name has not yet been released died in hospital in Belfast this monring.
A Sinn Féin councillor in south Armagh said he was "satisfied" no republicans were involved in the shooting.
Mr Packie McDonald said: "People in the area are naturally anxious to hear the full circumstances surrounding last night's events.
"This has come as a complete shock to people living here. Everyone I am sure will sympathise with the family who have received tragic news this morning, especially with us being so close to Christmas."
Earlier police were said to be investigating a possible INLA link to the shootings.