Families of murder victims are to ask prosecutors to review a decision not to bring prosecutions following a major investigation into a top army agent within the Provisional IRA.
Sixteen people, including ex-IRA members and security force personnel, were investigated as part of Operation Kenova.
In a statement on Wednesday, the Public Prosecution Service (PPS) said it has concluded there is insufficient evidence to provide a reasonable prospect of conviction for any of those reported.
A lawyer representing some of the families of victims said they are considering further legal action following the announcement of the decision by the PPS.
Sixteen people, six former security force personnel and members of the IRA, will not be prosecuted following a review of information gathered by the seven-year, £37m Operation Kenova.
Lawyer Kevin Winters, who represents some of the families of victims of British agent Stakeknife – alleged to be Freddie Scappattici and head of the IRA's notorious 'nutting squad' – described the decision as "a lost opportunity to explain why the PPS took over two years in some cases to reach these decisions".
"We have written to the PPS three weeks ago asking for clarification on what they knew about the main suspect's health condition in the lead up to his demise," Mr Winters said.
The PPS notice "was a chance to help dispel myth and rumour on his death and the timing out of decisions after his passing. The communication today only serves to fuel suspicion on the death of Scappaticci", he said.
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Decisions in relation to 21 individuals across 10 further files are expected to be announced in early 2024. A final Kenova report is due to be published next year.
The head of Operation Kenova, Sir Iain Livingstone, said the 16 people investigated were "supplementary" to the operation's main focus of investigating Stakeknife. Ten further cases are still being reviewed by the PPS.
"Kenova considers that we have gathered strong and compelling evidence in relation to that individual. Such evidence has been passed to the PPS and will form the basis of our interim and final reports," he said.
Mr Winters said that following the death of Scappaticci in April "all lingering hopes of criminal proceedings disappeared".
"Many viewed his death as timely and convenient because it helped block any meaningful criminal inquiry into how high were the levels of intelligence strata overseeing the PIRA ISU (Internal Security Unit) ...and Fred Scappaticci," Mr Winters said.
The PPS said there is "insufficient evidence" to bring charges, noting much of the evidence is based on intelligence records. These records cannot be used to bring prosecutions but will be included in the Kenova report. .