Government officials will examine in detail this week Irish and international extradition law amid a growing belief in legal and political circles that the extradition of the Colombia Three would be unlawful, write Mark Brennock, Chief Political Correspondent and Mark Duffy in Bogota.
Taoiseach Bertie Ahern has promised to consider any "request for assistance" from the Colombian government, and that the Government would "abide by its obligations under international law".
He acknowledged the return of the men had caused "an enormous amount of difficulties", and was "not helpful to the peace process".
In an article in today's Irish Times, Mr Ahern said "this country does not have an extradition treaty with Colombia".
Several legal sources said yesterday the absence of such a treaty made the prospect of the men being returned to Colombia - to serve jail sentences of up to 17 years for training Farc guerillas - remote.
In his article Mr Ahern calls for "calm and clear-headed" consideration and debate on the matter.
He leaves open the prospect of the men being tried here, possibly for travelling on false passports.
However, he also distanced the Government from any decision to proceed in this way.
"Any question of a breach of Irish law is a matter for investigation for the Garda Síochána and the independent office of the Director of Public Prosecutions."
He said the men's return had not been part of any deal with the Government, which had no prior knowledge of their return.
The director of operations of Colombia's administrative security department, Luz Miriam Rodriguez, told The Irish Times she would today ask the Colombian embassy in London to request the extradition of the three.
She said this could take some time, but her office had been preparing paperwork over the weekend.
Colombia's justice and interior minister Sabas Pretelt de la Vega said yesterday his government was studying mechanisms to bring the men back to Colombia.
His government "could not stand idly by with its arms crossed".
Colombia's attorney general Mario Iguaran said "international mechanisms do exist that enable us to issue an extradition request".
The Irish Government would not comment on whether it believes an extradition request from Colombia could succeed.
A spokesmen said the matter required more examination, and that no formal request had been received from Bogotá.
However, Irish legal sources said that the absence of an extradition treaty, and the fact that there appeared to be no international convention to which Ireland and Colombia had signed up and which covered the offences of which the three were convicted, suggested there was no legal basis for an extradition request.
Meanwhile Sinn Féin president Gerry Adams yesterday rejected claims the return to Ireland of the three - who jumped bail after being freed in March 2004 pending an appeal by the Colombian authorities against their acquittal on the charges of training Farc guerrillas - would cause a peace process crisis.
"These men should not be extradited under any circumstances whatsoever."