A man was being questioned today by detectives investigating the murder of a another man set alight with his girlfriend.
The man, 43, was detained by police as part of their probe into the shocking death of 33-year-old Thomas O’Hare.
He died in a Belfast hospital; his partner, Lisa McClatchey, 21, remains critically ill.
The couple were set on fire by self-styled vigilantes at their home near Keady, Co Armagh on Monday night.
Four brothers who have also been seriously burned and are recovering in a Dublin hospital are expected to be questioned about the arson attack.
A Police Service of Northern Ireland spokesman would today only confirm that the man being questioned was held in Northern Ireland.
He added: “He has been arrested today on suspicion of murder and attempted murder.”
Detectives believe up to six men were involved in the horrific attack when the couple were doused in petrol and their home set on fire.
Two men wanted in connection with the inquiry are believed to be on the run.
But none of the four brothers, aged between 24 and 34, are in a fit enough state to be questioned yet.
They are being treated at St James’s Hospital, in Dublin, with injuries ranging from 35% to 50% burns.
The four were first admitted to a hospital in Co Louth, just across the border from where the fire started. They arrived about an hour after the blaze.
Mr O’Hare, who had been separated from his wife and children for a number of years, died after failing to recover from his injuries.
Detectives are also believed to be investigating unconfirmed reports that he was threatened before the attack at his home on Foley Road.