The Operation Kenova interim report has revealed that some people under threat from the IRA’s feared Internal Security Unit (ISU) were never warned by state agencies.
In 2003 Belfast man Freddie Scappaticci, who died last year, was exposed as the Force Research Unit agent.
He was a former commander in the IRA’s Internal Security Unit, also known as the ‘Nutting Squad’.
The IRA unit was responsible for tracking down and killing informers.
The British government’s policy of ‘neither confirm nor deny’ (NCND) in relation to identifying agents means Scappaticci has not been officially named as Stakeknife.
Officials have been urged to review NCND in 10 recommendations published in the report.
The Public Prosecution Service was provided with files relating to Scappaticci in 2019 but he died before any decision was made.
The £40m Operation Kenova investigation, which ran for seven years, was published in Belfast on Friday.
Solicitor Kevin Winters represents families directly impacted by the Operation Kenova report.
The investigation is looking at 101 murders and abductions.
It highlights failings by state agencies and confirms that some individuals who were at risk of being kidnapped and interrogated were not warned and no action to protect them was taken.
The Kenova investigation team was originally headed by former Bedfordshire police chief Jon Boutcher.
He stepped down last year after he was appointed PSNI chief constable and was replaced by former Police Scotland chief Sir Iain Livingstone.
The long-awaited report called on the British government and republican leadership to apologise to the families of people killed by the ISU.
Sinn Fein vice president and Stormont First Minister Michelle O’Neill apologised to all victims of the Troubles.
“I am sorry for every single loss of life and that is without exception,” she said.
“That’s for every person who was hurt or impacted by our conflict.
“I think it’s important that today as the Sinn Fein new generation, Good Friday Agreement generation, that I would repeat that for those families.
“I can only hope - because this is ultimately their day - that they can take some comfort from that.”
The British government said it would not comment in detail on the Kenova probe until the final report was published.
Relatives of people killed by the ISU have welcomed the report’s publication, including Fran Mulhern.
His brother Joseph Mulhern was abducted and killed by the IRA in 1993 and it was claimed that he was an informer.
His father Frank later said he was given an account of his son’s death by Scappaticci.
“I welcome the release of the Kenova report, and thank Jon Boucher and the team for the work they’ve done and the obvious care and attention they have taken in producing it,” Mr Mulhern said.
“I welcome his recommendations and, in particular, the proposal for a day to remember all the victims of the Troubles.”
Mr Mulhern urged wider society to show compassion.
“Every single person in the province was a victim, whether physically or psychologically as a result of growing up in a civil war,” he said.
“To one degree or another we all suffered, and I would urge compassion from all sides when remembering and understanding the Troubles.”
His solicitor Kevin Winters, of KRW Law, suggested a public inquiry was needed.
“The report calls for apologies all round,” he said.
“Respectfully, this does not really cut it for some families.
“In many ways it represents a soft landing. As an alternative we say the report sign posts a way forward for a full public inquiry into state penetration of PIRA ISU during the Conflict.
“The Terms of Reference for Kenova were deliberately Freddie Scappaticci centric to the exclusion of investigation into other alleged agents working within that Unit.”
