However at least two of those responsible for their deaths were later uncovered as British agents within the IRA's Internal Security Unit, leaving the actual status of the Mahons as informers open to doubt.
When a number of IRA missions were compromised, Fenton is believed to have directed a member of the Internal Security Unit, Freddie Scappaticci, and three other men, to the Mahons.
Abducted in August, interrogated and beaten for prolonged periods, the Mahons eventually confessed that their flat was bugged by the Royal Ulster Constabulary, who are alleged to have paid the couple for information, another version is that the Mahons had agreed to inform on the IRA if the RUC overlooked a number of outstanding fines and charges they were facing.
One of the weapons hidden with the Mahons as a safe house was found by the IRA to have been fitted with a surveillance device.
They had both been tied by their wrists – but they must have broken free by struggling when they realised what was going to happen.Joe Hendron of the Social Democratic and Labour Party released a statement, remarking: This slaughter has few equals in barbarity and it proves the Provo idea of justice is warped.