The Irish National Liberation Army, which killed some 120 people during its violent campaign, is expected to officially announce it has decommissioned its weapons.
The terrorist group is expected to reveal on Monday that it has destroyed its illegal arsenal of weapons in a move which will be verified by Gen John de Chastelain.
The republican socialist paramilitary group, which was formed in 1974, was responsible for some of the most infamous attacks of the Troubles, including the killing of Conservative MP Airey Neave in 1979 and the massacre of three worshippers at Darkley Pentacostal Church in Co Armagh in 1983.
A republican source claimed the decommissioning happened in recent weeks.
“The announcement is expected on Monday,” he added.
Four months ago the INLA used a graveside oration outside Dublin to confirm its “armed struggle is over” and vowed to end its 35-year campaign of violence in Northern Ireland.
There was confusion however, regarding whether or not the group was prepared to decommission its illegal arsenal of weapons, after the statement read to supporters failed to promise a disposal of arms.