Nicholas Mullen was convicted at the Old Bailey in June 1990 for being part of a mainland IRA terrorist cell, linked to a major bomb factory in a flat in Clapham, south London. The cache found there was one of the biggest seen in Britain: it included 40 detonators, radio control and time-delay devices - and 106lbs of Semtex.
Mullen, 47, telephoned his solicitor, Michael Fisher, yesterday from Belmarsh prison asking him to start work immediately on an appeal.
This was because part of the evidence against him was the finding of traces of explosives in cars linked to Mullen, said Mr Fisher. "My client instructed me to lodge an application for leave to appeal," he said. "I am probably the first off the block on this one."
Mr Fisher said he was already preparing a long-planned appeal - based on the way Mullen was arrested in Zimbabwe - and had a transcript of the trial. "The judge summed up the evidence of the traces of explosives in the car by telling the jury: 'So there was Semtex then'. The question now is: was there?"
Mullen always claimed he was befriended by people he did not know were part of an IRA unit. He thought that they were fraudsters, and helped them find accommodation and vehicles, said Mr Fisher.
The number of terrorism convictions that could be overturned as a result of the findings is hard to estimate. Each case would depend on how central the evidence relating to explosives is likely to have been to the conviction, and the strength of other evidence. Convicted prisoners, like Mullen, who have not yet applied to appeal to the Court of Appeal would have their cases heard under the new Criminal Appeal Act 1995, which came into force in January and which makes appeals easier to pursue.
The case of Sean McNulty, jailed for 25 years in 1994 for a seven- week Semtex bombing campaign in north-east England, is another one that might reach the appeal court.
David Hammond, McNulty's solicitor, said yesterday that forensic evidence compiled at the Fort Halstead laboratory was the basis of the prosecution's claim that traces of RDX, a component of Semtex, were found on his car and clothing. The defence claimed in court that McNulty, 26, was not involved in the bombings, and traces of Semtex found at his home had been placed there accidentally by police who had visited the scenes of the bombings. The rest of the evidence was circumstantial. McNulty has already lodged an application for leave to appeal.
Another potential appellant might be Hugh Jack, sentenced to 20 years in 1995 for conspiring to cause explosions by storing Semtex and other bomb- making equipment.
Fall of forensic science? page 21