Michael McKevitt, aged 54, claims he did not get a fair trial because his legal team had not been supplied with all information in relation to a key witness, FBI agent David Rupert.
The trial had failed to have an appropriate system of disclosure of documents which were crucial to his case, his lawyer argued in the Supreme Court yesterday.
The disclosure would have included information about Mr Rupert having been allegedly investigated for fraud in 1974 and 1994 which went to motivation for him acting as an informer for the FBI, said Hugh Hartnett SC for McKevitt.
Mr Rupert was described in a report by an American state trooper as being involved in theft and people/arms smuggling between the US and Canada using a trucking firm he had set up, said Mr Hartnett.
His failure to be prosecuted for these activities and later being signed up by the FBI went to the integrity of his motivation for giving evidence in the case against McKevitt, counsel said. The omission of that material should have been addressed in his trial, counsel said.
Had it been provided, it would have shown the secret services’s “attempt to mask” Mr Rupert’s alleged criminality, said Mr Hartnett.
No schedule of documentation was ever presented to the defence and McKevitt’s lawyers got material relating to Mr Rupert’s alleged criminality “by chance or mistake”, said Mr Hartnett.
The lawyer was speaking on the opening day of the Supreme Court appeal by McKevitt, of Beech Park, Blackrock, Co Louth, who was jailed for 20 years by the Special Criminal Court in August 2003 for organising terrorist activities for the Real IRA.
A key part of the case was the evidence of Mr Rupert, who was described by the judges who convicted McKevitt as “very truthful” and rejected defence attempts to discredit him.
He appealed to the Court of Criminal Appeal (CCA) which upheld the conviction in 2005.
The five-judge Supreme Court is hearing the appeal against the CCA decision.