O'Hare (33) died on Friday morning at Royal Victoria Hospital in Belfast from wounds received in the attack carried out by a gang of up to six men on his home in Keady, South Armagh. His girlfriend, Lisa McClatchey (21), was also in the house at the time of the attack and remains in critical condition. The attack occurred last Monday night.

The four Smith brothers, Martin, Nigel, Stephen and Christopher . . . all from nearby Clady in south Armagh . . .

were transferred from Louth County Hospital to the specialist burns unit at Dublin's Saint James's hospital where they are being treated for their injuries.

It initially appeared that the four men received their burns while carrying out the arson attack on O'Hare's home.

However, the Sunday Tribune has learned that PSNI officers last week discovered a vehicle burned out at Loughran's quarry in Keady, and that this is being forensically examined to determine if this was one of the get-away cars being driven by the arson gang.

A spokesman for the company which runs the quarry in which the burnt car was found, Loughran Rock Industries, yesterday told the Sunday Tribune that the damaged car had been removed from the scene by the PSNI. "They took it away. They didn't say if it was in relation to the [arson attack], just that they were looking into the likelihood that it may be".

Among the theories being examined is whether ignition fuel had been splashed on the men's clothing during the arson attack and that the vehicle set alight at a higher intensity than they had planned for . . . also setting them on fire.

It is believed that the remaining two gang members brought the injured brothers to the Dundalk hospital.

It is understood that the other two members of the arson gang are not relatives of the four Smith brothers.

The PSNI want to interview the Smith brothers, aged between 24 and 34, about the attack in which the couple were allegedly doused in petrol, but they remain too ill to face questioning. Two of the four brothers remain in a critical condition and it is understood that one of the men was anointed by a priest twice in past days.

A 43-year-old Co Armagh man is being interrogated by murder inquiry detectives.

A source told the Sunday Tribune that O'Hare had been linked to a sex assault against a member of the Smith family when the individual was a child. One theory being investigated by detectives is that the fire was a revenge attack.

O'Hare had been placed on the sex-offenders register around seven years ago following his conviction and shortly afterwards left his native Clady to live in Portadown, only returning recently to occupy a house left to him by a deceased uncle.

A PSNI spokesman declined to comment on whether the motive for the attack was in any way related to O'Hare's previous conviction.

O'Hare, a Catholic, was living on-and-off with McClatchey in the bungalow in an isolated spot on the outskirts of Keady. McClatchey, a Protestant from the Kilicomaine estate in Portadown, is the grand-daughter through marriage of the late Harold Gracey, the Orange Order leader who was at the centre of the Drumcree dispute. It is understood that some of her relatives disapproved of her relationship. McClatchey, who is being treated for 80% burns, remains critically ill.

Her family are at her side.

O'Hare separated from his wife three years ago. They have two children under-12.

O'Hare's parents, Benny and Margaret, live in the village of Cladymore, not far from where their son set up home.

The Smiths are cousins of local SDLP councillor Sharon Haughey, but local people said they had little contact with her and did not support her in last year's local government elections.

Haughey has condemned the attack. "No-one has the right to act as judge, jury and executioner, " she said.