Two men and a boy being held by detectives investigating the murder of a man in Belfast on Saturday have been released.
Robbie Lawlor (36) was shot dead in Etna Drive in Ardoyne.
The PSNI said last night that two men aged 30 and 33 and a 17-year-old boy had been released unconditionally.
A 27-year-old man who was also being questioned by police was released unconditionally on Monday.
One of the Limerick men released is a notorious criminal who is a central figure within the McCarthy/Dundon gang.
The thug was only released from prison in recent weeks after serving a lengthy sentence for firearms offences.
The juvenile is a close associate of convicted killer John Dundon, currently serving a life sentence for the murder of innocent rugby player Shane Geoghegan in 2008.
Meanwhile, Irish mob boss Wayne Dundon and his killer brother have been celebrating the murder of gangland hitman Lawlor.
Two senior members of the notorious McCarthy/Dundon crime gang are suspected of double crossing the Dublin criminal.
Lawlor (36) was the chief suspect in at least six murders, including the abduction and dismemberment of 17-year-old Keane Mulready-Woods.
Lawlor was shot dead by a lone gunman.
It has been learned that convicted killers Wayne and Dessie Dundon have been openly celebrating the murder behind bars in recent days from their cell in Dublin's Mountjoy Prison.
A source said: "They have been cheering and celebrating since Saturday, they're walking around with their chests out.
"Neither are saying they were involved of course, but they're happy out going around the jail, they aren't subtle about it either."
Wayne Dundon (41) is currently serving a life sentence for the murder of innocent businessman Roy Collins in Limerick in 2009.
His younger brother Dessie (35) is also serving a life sentence after he was convicted of involvement in the murder of Kieran Keane in 2003.
The Garda is liaising with the PSNI in relation to the murder of Lawlor and believe he travelled to Belfast with three Limerick males to collect a drug debt before being shot dead.
The killer made his getaway after entering and leaving the property through a back door.
A car thought to have been used to transport the gunman to the house, a 2010 Volkswagen Sirocco, was set alight nearby but the handgun used in the murder has not been recovered.