The Director of Public Prosecutions (DPP) has told the Supreme Court there is "no substance" to claims that all available and relevant material was not fully disclosed to lawyers for Co Louth man Michael McKevitt for his trial on a charge of directing terrorism.
Lawyers for McKevitt had failed to show that many of the documents sought by them were relevant, Donal O'Donnell SC, for the DPP, also said.
He was opening arguments for the DPP opposing the appeal by McKevitt against his conviction for organising terrorist activities for the Real IRA.
He was convicted following a trial before the non-jury Special Criminal Court in 2003 and was jailed for 20 years.
McKevitt (54), Beech Park, Blackrock, Co Louth, is the first person in the State to be convicted of directing terrorism under laws brought in following the 1998 Omagh bombing in which 29 people, including a woman pregnant with twins, died.McKevitt claims he did not receive a fair trial on a number of grounds.
He claims the key prosecution witness, FBI agent David Rupert, had no credibility and that there was no appropriate system of disclosure of documents by the prosecution.
His lawyers have argued the disclosure would have included information about surveillance notes of McKevitt's attendance at a Real IRA army council meeting in February 2000 which was attended by Mr Rupert. They also say the material included information about Mr Rupert having been allegedly investigated for fraud in 1974 and 1994.
Such material, it is contended, is relevant to Mr Rupert's motivation in acting as an informer for the FBI.
Yesterday, Mr O'Donnell said the height of the defence case over the allegedly missing material related to disclosure of information by foreign authorities, the FBI and the British secret service.
The defence had not satisfied a test which showed the material was relevant, counsel said. They had also not shown that, if it was relevant, it was not subject to confidentiality. Among the materials were 2,300 e-mails which were paginated and in chronological order, he added.
There was no substance to claims by McKevitt's lawyers that a proper schedule had not been attached to the documents provided so that the defence could examine them, counsel said. The Court of Criminal Appeal had correctly analysed the documents and made no error in that regard, he added.
Mr O'Donnell also said that, in obtaining disclosure of material through the American and British courts, McKevitt had had unlimited assistance of lawyers from those countries who were paid for by the State. They attended his trial and were there to take steps or "second guess" in relation to whether proper disclosure had been made, he argued.
In their submissions in the appeal, McKevitt's lawyers said that the omission of material about Mr Rupert's past activities should have been addressed by the trial court. Had the material been provided, it would have shown the "attempt to mask" Mr Rupert's alleged criminality, it was submitted.
Mr Rupert was "a life-long criminal" and when convicting McKevitt on the evidence of Mr Rupert, the Special Criminal Court had failed to address Mr Rupert's past activities, Michael O'Higgins SC said.
The appeal resumes on Monday when it is expected to conclude with judgment reserved.