Guns used by loyalists to murder 18 people, including four in Lurgan, will be a major feature at a preliminary hearing opening this week into one double killing.
And there have been calls for a judge-led inquiry following revelations that the weapons used to murder Charles Fox and his wife Theresa in Moy in 1992 were also used in a number of other murders and attempted murders across north Armagh and Tyrone.
The couple were shot dead with a Czech-made VZ58 automatic rifle which was one of two used to kill 18 people between 1988 and 1994.
One of the guns is thought to have been used in the murder of Denis Carville at Oxford Island near Lurgan on October 6, 1990.
The guns are also linked to the triple murder on November 14, 1991 of father of three Dessie Rodgers, Fergus Magee a father of one and John Lavery a Protestant father of three. They had been shot as they left a forklift factory near Lurgan.
Full details of both weapons emerged during a high profile inquest into the murdered Co Tyrone pensioner Roseann Mallon.
The guns are believed to be part of a large cache of arms smuggled into Northern Ireland with the help of paid British agent and UDA intelligence officer Brian Nelson in 1998.
Ms Mallon was shot dead as she watched TV and it later emerged that undercover British soldiers, who looked on as the pensioner was murdered, were ordered not to intervene.
It is understood that details of the weapon used came to light after an official connected to the Historical Enquiries Team contacted legal authorities during last year’s inquest and revealed its history.
The weapon which was recovered in 1994 was said by authorities to have no previous history when in fact it was used to kill six people including Mr and Mrs Fox.
Relatives for Justice spokesperson Mark Thompson said a judge-led inquiry is needed to explore the full extent of security force collusion with loyalists in mid-Ulster claiming there would be no confidence in a PSNI-led investigation after past failures.