A fourth man has been arrested in connection to the murder of Andrew O'Donoghue who died after he was shot outside a motorcycle clubhouse in a rural area of east Limerick over the weekend.
The man in his late forties was arrested in Limerick City this morning.
He is currently detained at Henry Street Garda Station. Gardai said investigations are still continuing.
It is believed biker Andrew O'Donoghue (51) was shot dead after a growing feud between two rival biker clubs turned violent.
A motorcyclist who had been in a dispute with Road Tramps Motorcycle Club, of which the victim was a member, is the chief suspect for the horrific murder.
In recent times, the suspected killer has become involved with a different club and tensions between the rival motorcycle clubs escalated, culminating in the murder of Mr O'Donoghue.
The father of one, whose nickname was 'Odd', was shot in the head outside the clubhouse at Mountfune, Murroe, Co Limerick, at 3pm on Saturday. It is believed that the assailant was armed with a shotgun.
Mr O'Donoghue, who lived in the Cois na Coille estate in Murroe, was rushed the 22km journey to University Hospital Limerick but died there from his injuries a short time later.
At least eight people were in the vicinity when the gunman opened fire before he fled from the area.
Gardaí are also examining CCTV footage from the rural clubhouse in a bid to determine what exactly happened at the scene.
It is not yet established if there had been an arranged meeting or whether it was a chance encounter.
Three men aged in their 40s and 20s were arrested by gardaí in the Limerick area on Saturday night.
They were being questioned at Henry Street and Roxboro garda stations in Limerick city and can be questioned for up to seven days before a decision is made to release or charge them with an offence.
Officers are also interviewing residents in the area surrounding the clubhouse in a bid to see if they saw or heard anything.
The club to which the suspected killer is aligned is believed to be made up of people who had been thrown out of other motorcycle clubs.
They came together to form their own club and it is believed they were trying to exert their authority on more established and well known Irish motorcycle clubs.
Mr O'Donoghue has a daughter with his long-term partner and had never been in trouble with gardaí.
The club, founded in 1987, was previously known as 'The Reapers' and its members are well known in the east Limerick area. They regularly socialise in pubs in the area and are well regarded.
"They have been here for donkey's years and there has never been a problem with any of them. Everyone would be well used to seeing the lads touring around on their motorbikes or out having a drink like the rest of us," one local in Murroe said last night.
Murroe Parish Priest Fr Tom Ryan knew Mr O'Donoghue well.
"I looked upon Andrew as a good friend. I really can't accept why this happened and why it happened to him," Fr Ryan said yesterday morning.
"He led a peaceful life.
"I heard yesterday on the 6pm news. I knew Andrew very well.
"He was quiet, an inoffensive man, he was a good friend of mine. He lived in the village and he had a serious interest in motorbikes," Fr Ryan said.
"I'm quite shocked to hear this has happened," the priest added.