The funeral of Gerard 'Jock' Davison as it leaves his family home in the Markets area of South Belfast. Pic Kevin Scott / Presseye
They are Brendan Devine, who fought with Jock Davison minutes before Robert McCartney was stabbed to death in Magennis’ bar in 2005.
The 41-year-old was later freed after detectives accepted he had absolutely nothing to do with the fatal shooting.
Also arrested was Scott McHugh, 27, whose uncle has children with Davison’s sister.
He is the grandson of IRA murder victim Anthony ‘Monkey’ McKiernan who was killed in 1988 over informant allegations. McHugh — who was questioned by cops about a dissident republican shooting in the Markets four years ago — had clashed with Davison in recent weeks.
He too was freed unconditionally after strongly denying any involvement and having attended a PSNI station voluntarily.
A 38-year-old man from the Markets was the third man arrested on Thursday night, but released two hours later.
He had absolutely nothing to do with the murder and was out of the country on holiday at the time.
Security sources say that because Davison had so many enemies from his time in the IRA they are duty-bound to chase every lead — even if it means arresting the wrong people.
What they are now focusing on though is the scenario that his killer was a professional hitman, paid for by the friends of drug dealers murdered by Direct Action Against Drugs.
Davison, who was about to become a grandfather for the fourth time, led the vigilante group which started off its killing campaign in 1995 when it gunned down his Short Strand neighbour Mickey ‘Moneybags’ Mooney.
Three years earlier the republican, then aged 24, committed his first murder — shooting dead IPLO leader Sammy Ward in the St Matthew’s Social Club during a feud with the IRA.
After this Davison — whose uncle was murdered IRA boss Brendan ‘Ruby’ Davison — quickly rose through the Provo ranks and by the late 1990s became its leader in Belfast.
He was then promoted to Northern Command, but was stood down in 2005 after the shameful bar-room murder of Robert McCartney.
Despite cutting ties with the Provos soon after, he remained on good terms with its senior figures and enjoyed a close friendship with ex-IRA Army Council member Brian Gillen.
In later years Davison was employed as a community worker in the Markets Development Association — the office where he was walking to when he was murdered last Tuesday.
Cops investigating the killing have appealed for information, with Detective Chief Inspector Justyn Galloway saying: “From our inquiries we believe the gunman was wearing a black hooded waterproof jacket.
“We believe he may have been waiting for Jock to walk past on his way to work at the junction of Lower Stanfield Street and Welsh Street. We need to speak to anyone who thinks they saw this individual.”
“At another level, we still face many challenges in terms of the information coming to us and how we act on this in order to progress the investigation,” added DCI Galloway.
“That’s going to raise issues in terms of the inquiries we have to make, the people we need to speak to, the doors we need to knock and the arrests and searches we make.
“Our objective will always be to conduct a thorough, professional investigation.”
Anyone with information on the Jock Davison murder should contact detectives at Musgrave Street station or the Crimestoppers charity on 08000 555 111.