VICTIMS of republican violence have paid tribute to Sean O'Callaghan after the IRA informer drowned in a swimming pool in Jamaica.
Relatives of those killed in the Kingsmill massacre and Omagh bomb said he had been "hugely helpful" in their fight for justice.
However, other IRA victims said that those O'Callaghan had murdered must not be written out of the narrative in a rush to portray him as a hero.
A native of Co Kerry, 63-year-old O'Callaghan died in the Caribbean while visiting his daughter. He had been living in England under the threat of reprisal from former IRA associates ever since he went public about his life as a spy.
O'Callaghan detailed the inner workings of the IRA in his best-selling book The Informer in 1999.
Among his revelations was the claim he thwarted a plot to murder the Prince of Wales and Princess Diana in the 1980s.
He was jailed in the 1990s after walking into a police station in England and admitting two IRA murders. He was released in 1997.
Both mainstream and dissident republicans dismissed O'Callaghan as a Walter Mitty-style character whose claims were embellished or untrue. He joined the IRA in the 1970s but turned informer and began providing information to the Garda.
Michael Gallagher, whose son Aiden was one of the 29 people killed in the Real IRA's 1998 Omagh bomb, said: "Sean O'Callaghan helped us hugely in the civil action that we took against certain republicans.
"We will always be so grateful to him for his assistance.
"At that time there weren't too many people willing to help us and he was always there and ready to do whatever he could. He was invaluable because he knew the modus operandi of republicans and he also had personal knowledge of some senior figures."
Mr Gallagher said he was shocked to learn of O'Callaghan's premature death, and while he personally didn't "agree with him on everything", they could always "agree to disagree".
Earlier this year O'Callaghan gave evidence from a secret location to a Belfast inquest examining the IRA murder of 10 Protestant workmen near the south Armagh village of Kingsmill in 1976. He named two senior Provisionals as being responsible.
Victims' campaigner Willie Frazer last night said he wished to sincerely thank him for his help.
"Sean O'Callaghan was once an IRA gunman, a convicted killer - his past actions must be loathed and condemned," he said.
"We must, however, recognise the huge contribution that Mr O'Callaghan played in exposing the brutal realities of the IRA campaign. Intelligence which he provided set about righting many of the wrongs he himself was involved in."
Mr Frazer described O'Callaghan's testimony to the Kingsmill inquest as open and transparent.
"He detailed the IRA's sectarian war, their ethnic cleansing agenda," he said.
"I and the families thank him for his involvement and vital evidence which now stands as historic record."
Mr Frazer described O'Callaghan's death as a "loss to the legacy process" and sent his condolences to the informer's family.
However, Innocent Victims United spokesman Kenny Donaldson said that O'Callaghan's own violent past must be at the forefront of any narrative remembering him.
He added: "Many from a broadly unionist background never fully trusted him and saw him through eyes of cynicism - that he was used as an example of the republican movement's remorse for the past and the opportunity for a new way forward, via the Belfast Agreement.
"If his remorse was genuine then he has been proven to have been more so the exception and certainly not the rule."
Mr Donaldson said others spoke favourably of O'Callaghan for exposing "the lies and evils of a terror movement" in his later years. But he said that his group's first concern was for the families of UDR Greenfinch Eva Martin and Special Branch detective Peter Flanagan whom O'Callaghan admitted murdering.
"Neither Eva nor Peter can be brought back, their lives were stolen and their families were left broken," he added.
"Eva and Peter had no opportunity to live their lives, that was taken away from them.
"Was Sean O'Callaghan genuinely remorseful for the grievous harms he caused to their families and most probably many others?
"Did he repent for his crimes and sins and did he publicly and privately seek to restitute for the wrongs he inflicted? Those are all questions that only he and God know the answer to."
Mr Donaldson said that as journalists and politicians pontificated about the informer's life "please do not forget Sean O'Callaghan's victims - the innocents who are the real heroes and martyrs within this society".