An informer saved the life of campaigning father Raymond McCord as he worked to expose the agents who killed his son.
As a debate about the police use of informants continued today, Mr McCord revealed "the irony" of the agent who prevented UVF attempts to silence him - although he says he is certain the informer never crossed the line into murder like Mark Haddock.
Mr McCord spent almost 10 years digging for information about the 1997 murder of his eldest son, Raymond Jnr.
On Monday, a report by Police Ombudsman Nuala O'Loan said a UVF informer - already identified as Mark Haddock - and other agents were involved in the murder of Raymond McCord Jnr and at least nine other killings.
The report indicated that some police officers knew about Haddock's involvement in crime and protected him from prosecution. The report has sparked a huge public debate about whether informers saved lives or were allowed to get away with murder.
Mr McCord has seen both sides of the argument. He says his son might be alive today if police had prosecuted Haddock when they first knew he was involved in crime.
But he says his own life was saved by an informer - allowing him to reach his goal.
However, he says he knows the identity of that informer and says he has worked within acceptable limits of the law.
There were a series of UVF threats and plots to kill Mr McCord as he worked to expose his son's killers. His most recent warning came on Saturday.
"There's been many, many threats to my life," he said. " Police got wind through an informer that they were going to try to shoot me in different places.
"The irony of it - an informer saved my life. I know who that informer is. I was able to find out. And I know that informer was not involved in murder.
"I know people will turn around and say, 'ah Raymond McCord's just saying that'.
"I can tell you - I'm not going to sit and tell lies over Raymond's case. It's not my case, it's Raymond's case and I'm not going to tell lies over it. But the man saved my life."
Earlier this week Mrs O'Loan told the Belfast Telegraph that she feared Mr McCord could be murdered before her investigation was complete.
She said she made representations to the police about Mr McCord's security and did not share information with him during the course of her investigation in case it heightened the risk of a murder bid.