Paramilitaries may have been involved in the murder of a former associate more than four years ago, it has been revealed.
Mark Gourley, 36, who was once described in court as a loyalist footsoldier, has not been seen since March 2009.
His body has never been recovered.
At a press conference in Belfast a senior detective said he was convinced Gourley had been murdered and declined to rule out paramilitary involvement in his death.
Detective Inspector Neil McGuinness, from the Police Service of Northern Ireland (PSNI) said: “At the time of his disappearance Mark Gourley was not an active member of a paramilitary organisation. I don’t believe he ever was a senior member of any paramilitary organisation although in his past he did have associations with groupings.”
The officer said new information had led police to re-examine the case and launch a murder hunt.
“At this stage I can’t go into the detail of that information but it convinces me and my team that Mark Gourley has been murdered and we are appealing for anyone to give us assistance to that,” added Mr McGuinness.
He said investigators were following a number of lines of inquiry but declined to be drawn on claims Gourley had owed money to loyalists.
“All lines of inquiry are being looked at and will be followed up appropriately.”
Mark Gourley, from the Castlemara area of Carrickfergus, Co Antrim was last seen in the Bernie’s Lane area of Glengormley at about 2.30pm on March 7, 2009.
He was described by police as “vulnerable” and was on medication at the time of his disappearance.
Also, he did not have a phone or a significant amount of money.
In 2005 Gourley was handed 18 months’ probation for his part in an attack on an undercover police officer investigating alleged extortion in Carrickfergus.
Mr McGuinness said: “Police are asking for anyone who may have noticed vehicles or individuals acting suspiciously in either the Bernie’s Lane area of Glengormley or in the Castlemara area of Carrickfergus to contact police.
“Police believe there are people in these areas who have knowledge of what has happened to Mark.”
In the past republicans have admitted to abducting, murdering and secretly burying victims during the Troubles.
The Independent Commission for the Location of Victims’ Remains, which was set up to find the bodies of the so-called “disappeared” can only investigate cases up until 1998.