Families of four UVF murder victims have obtained a draft police report which links UDR soldiers to a 1991 attack.
The report into the shootings at Boyle’s Bar in Cappagh was compiled by the Historical Enquiries Team.
It states months after the attack, intelligence was received which “named three serving members of the UDR as being responsible”.
They were questioned, along with “a close associate”, but never charged.
Three of the four men murdered were members of the IRA – Malcolm Nugent (20), John Quinn (23) and Dwayne O’Donnell (17).
They were shot as their car pulled up outside the County Tyrone pub.
The fourth victim – 52-year-old Thomas Armstrong – was killed in the bar seconds later by shots aimed through a window.
The men’s families have always maintained the attack involved collusion and the Ulster Defence Regiment (UDR) connection has been claimed previously by victims’ group, Relatives for Justice.
A solicitor representing some of them, Gavin Booth of Phoenix Law, said it is “the first time a state report confirms collusion” in the case.
He added: “The families remain committed to obtaining the truth.”
They hope to meet with the PSNI soon to discuss the case.
The report, which focuses on the death of Mr O’Donnell, also raises the possible involvement of MI5 in several murders in the area.
It states the arrest of the soldiers in 1991 followed work by a joint police and army team which reviewed “concerns of security service collusion in east Tyrone”.
It adds “the same men were also named as responsible for other murders”.
Two other men had previously been arrested immediately after the Cappagh murders – one of them reportedly being the late UVF leader Billy Wright.
The report also connects the two VZ58 rifles used in the attack to 11 other incidents between 1988 and 1993, including the UVF murders of Charles and Theresa Fox in Moy in 1992.
It stated a review of the Boyle’s Bar case in 2002 concluded there were no new lines of inquiry or investigative opportunities which could lead to the identification or prosecution of those involved.