A victims’ group is set to ask a new legacy body to look at the killing of eight workers at an Army barracks in Co Tyrone in 1992.
No one has ever been charged or convicted over the Teebane attack by the Provisional IRA.
Ulster Human Rights Watch (UHRW) said they will be asking the Independent Commission for Reconciliation and Information Recovery (ICRIR) to find answers to questions which the grieving families have never had.
The ICRIR was set up in the UK’s Legacy Act and is headed by Northern Ireland’s former lord chief justice Sir Declan Morgan.
It will investigate unsolved Troubles killings and will have the power to offer conditional immunity from prosecution.
It is set to take up work on a number of inquests into events from the region’s troubled past which have not completed by May 1.
UHRW advocacy manager Axel Schmidt described Teebane as “one of the worst terrorist atrocities” of the Troubles.
“This case should now be investigated by the ICRIR to answer important questions concerning the criminal investigation and the absence of protection given to the 14 Karl Construction employees by the RUC,” he said.
“Teebane was one of the worst terrorist atrocities carried out during the Troubles.
“Civilians working on the Lisanelly Army Barracks in Omagh were murdered because they were working for the security forces. It was cold-blooded, brutal and senseless.
“For years, the families have been searching for answers about the conduct of the investigation by the RUC. To say that it was insufficient and ineffective would be an understatement.”
He said UHRW will pass on a detailed file to the ICRIR, and will ask the body to look at the police investigation and what security arrangements were in place to protect the workers.
“Crucially, we also raise the failure to arrest and question some suspects,” he said.