Campaigners for the three republicans sentenced to jail for training Marxist rebels in Colombia have vowed to get the decision overturned.
Arrest warrants have been issued for the three men
Niall Connolly, Martin McCauley and James Monaghan were sentenced to 17 years after an appeal court reversed their earlier acquittal on the charge.
The men vanished while on bail awaiting Thursday's court of appeal decision.
Sinn Fein MLA Caitriona Ruane accused Colombia's attorney general of bringing its legal system into disrepute.
Speaking at a press conference in Colombia on Monday, she said: "This is a travesty of justice of international proportions.
"The lawyers are now exploring ever legal option left open to the three men.
"We are planning to bring the case of the three Irish men, EU citizens, to the European Parliament.
"This campaign will continue, it will intensify and we will further internationalise it."
The lawyers and campaigners are considering an appeal to the country's Supreme Court.
On Sunday, Irish Prime Minister Bertie Ahern said: "We don't have presently an extradition agreement with Colombia. We will have to look at the legal aspects that arise.
"One of the three was carrying an Irish passport and there could be legal
matters around that. They probably served their sentence on that. So I think all
of the legal matters will have to be looked at."
He added: "I think people felt the judge on the first hearing was a reasonably fair person.
"Then you go on an appeal and you end up getting 17 years so on the face of
it that looks very difficult."
There are reports the Colombian authorities have asked Interpol for help in tracing the men.
'Fled from Colombia'
Colombian Attorney General Luis Camilo Osorio is reported to have told Reuters news agency on Friday that they would try to establish where the trio had gone.
The men, who had been accused of being IRA members, were found guilty in the April trial of travelling on false passports.
They were acquitted of training Farc guerrillas, but the Colombian attorney general appealed against that decision.
A judge had ordered the men to remain in the country pending the outcome of the appeal.
McCauley, 41, is from Lurgan in County Armagh, Monaghan, 58, is from County Donegal and Connolly, 38, is from Dublin.
The three had been detained at Bogota's El Dorado airport in August 2001 as they were about to board a flight out of the country.
Their arrest led to speculation that Irish republicans had formed links with the Revolutionary Armed Forces of Colombia (Farc).
The main charge against them was that they had been teaching the rebels urban terrorism techniques.
The Irishmen strenuously denied this, saying they were in the area to monitor the fledgling peace process as well as being eco-tourists.