Three republican suspects awaiting trial in Colombia are set to have their case heard early next month, according to representatives of the Bring Them Home campaign.
Martin McCauley, James Monaghan and Niall Connolly were arrested in August 2001 on suspicion of training leftist guerrillas of the Revolutionary Armed Forces of Colombia (FARC).
Last month proceedings against the three were adjourned after two prosecution witnesses failed to give evidence.
The authorities were unable to contact John Alexander Rodriguez Caviedes, a deserter from the Colombian guerrilla force FARC, to bring him to court in the capital Bogota.
Colombian media reports claimed that the witness would have testified to meeting the three Irishmen inside a rebel safe haven in southern Colombia in 1999, when the men brought rocket launchers to sell to FARC.
Prosecutors said it was too dangerous to transfer a second witness Edwin Giovanny Rodriguez to the court.
But last night (Sunday) Bring Them Home campaigner Caitriona Ruane said the Colombian authorities had now "found" Caviedes and that he was under a state-run witness protection programme.
Ms Ruane claimed that in a letter to judge Jairo Acosta, representatives from the witness protection programme said they could not afford for the witness to travel to proceedings in Bogota.
A judge based in the northern Colombian city of Medellin will instead be asked to take written evidence from the witness, with defence lawyers submitting their questions in writing.
Last night Ms Ruane branded the situation "farcical" and said an air fare from Medellin to Bogota cost $200.
"Mr Caviedes is a key witness and it is essential that our lawyers have an opportunity to cross-examine him," she said.
"They have not even told us where or by whom his evidence is to be taken."
Ms Ruane also criticised the Colombian authorities for housing the three Irish suspects in a jail for sentenced prisoners.
She said that despite assurances to the Irish government and international observers, the men had been moved to a prison outside Bogota.
"It is a very harsh regime and they have removed all their books from them claiming they are subversive," she said.
"The men have been subjected to strip searching and visitors are also strip searched by prison officers.
"It is dangerous and difficult for lawyers and family members to visit them."
