The European Court of Human Rights has found that the trial of two men found liable over the Omagh bomb in a civil case was not unfair.
While there has never been a criminal prosecution over the atrocity, Michael McKevitt and Liam Campbell were among the defendants in a civil case brought by families of the victims.
The action was successful, and they were ordered to pay substantial damages.
The pair then complained to the European Court that the trial had been unfair.
They claimed that the first instance court should have applied a criminal rather than civil standard of proof, due to the severity of the allegations against them.
They further claimed that the admission of the evidence of an FBI agent who had not been made available in court for questioning was unfair.
However, the European Court has now dismissed the complaints.
It found that a criminal standard of proof was not necessary because the proceedings had been for a civil claim for damages and there was no criminal charge.
It also found the judge had fully considered the need for appropriate safeguards regarding the absent FBI agent; that the defendants had had an adequate opportunity to challenge the agent’s evidence with their own; and that the judge had had due regard to the appropriate considerations when deciding what weight he could attach to the evidence of an absent witness.
The Omagh bomb detonated in the centre of the Co Tyrone town on the afternoon of 15 August 1998, killing 29 people - including a woman pregnant with twins.
McKevitt is currently jailed in Portlaoise, while Campbell is in HMP Maghaberry.