Among the cases that could be affected are those relating to bombings at the Royal Marines' School of Music in Deal, Kent, in which 11 bandsmen died, and the case brought against three men accused of planning the huge explosion at Warrington Gasworks.
Those who may have a case for appeal include Feilim O'Hadhmaill, 36, a university lecturer from Accrington who was caught with Semtex in the boot of his car. A search subsequently uncovered a list of military, economic and political targets, including Cabinet ministers and MPs with declared interests in Northern Ireland.
Nevertheless, his 25-year sentence, relate to the discovery and analysis of 37lb of Semtex found in his car.
Three men involved in the 1993 Warrington Gasworks bombing, after which a police officer was shot but survived, may have their cases reviewed.
Pairic MacFhloinn, serving 35 years for planting the bomb, Denis Kinsella, who assisted him, and John Kinsella, who has always denied being the quartermaster for the operation, were all convicted wholly or partly on tests on the Semtex they were alleged to have used.
Yesterday's news will have been welcomed by supporters of Kinsella, 51, who is serving 16 years. A growing number of supporters, including British and Irish MPs, accept he believed he was being asked to store stolen goods, not Semtex and guns. They point out that he buried the booty in an allotment under a spot used by the owner to build small bonfires.
Also believed to be under consideration are Damien McComb, 32, and Liam O'Dhuibhir who were arrested after visiting a hidden Semtex dump on the south Wales coast in 1990.
Police, who believed the Semtex was used in the Deal barracks bombing, kept the cache under surveillance for 42 days before arresting the men when they came to recover it. They were never charged with the Deal attack, but they were jailed for 30 years for conspiring to cause explosions.
Robert Fryers, 44, stored 2.5 kilos of Semtex at the home of his accomplice, Hugh Jack, before packing it into a holdall with two litres of petrol in what police described as a napalm-like device. The bomb failed to go off, but the men were jailed for 25 and 20 years respectively in January 1995. The evidence relating to their Semtex is thought to be among that being reviewed.
Similarly, the case of Liam McCotter, 31, serving 17 years for hiding 190lb of Semtex in forests around the Midlands, could also come under review.Reuse content