An alleged incident at Bogota's El Dorado Airport involving Mr Paul Hill of the Guildford Four is being raised with the Minister for Foreign Affairs, Mr Cowen, and the Ministry of Foreign Affairs in Colombia. It is also due to be raised in the Dáil this week.
Mr Hill, who was wrongly imprisoned for 15 years in Britain before being released as an innocent man, was a member of an observer group at the trial of the so-called Colombia Three.
According to the Bring Them Home Campaign, which organised the observer group, a Colombian immigration official from the Department for the Administration of Security "ripped" Mr Hill's passport out of its cover while he was about to board an Air France flight for Paris last Thursday, before travelling on to Dublin.
A Dublin barrister, Mr Ronan Munro, who was also observing the trial, has written in a personal capacity to Mr Cowen to express his "outrage" at the incident.
He claimed in the letter that "the immigration official, after stamping Mr Hill's passport, ripped it in two, (i.e., the cover from the pages) before handing it back. Mr Hill's visa, affixed to his passport, states that the purpose of his visit was to observe the trial of the three Irishmen".
The letter continued: "When the officials were informed that we were travelling under the protection of the Colombian Minister for Foreign Affairs, they were apparently unconcerned. Mr Hill noted that the officials were of the same state agency which provided prosecution evidence in the case against the three Irishmen."
Ms Caitríona Ruane, spokeswoman for the Bring Them Home Campaign, claimed that when she raised the incident with an immigration supervisor, he refused to give the name of the official concerned or even his own name.
She claimed the supervisor had turned his identity badge around "deliberately" so that she could not see his name. When she leaned over to turn it back again, "he grabbed my wrist in a violent, abrupt manner".
The observer group included two TDs, Mr Seán Crowe of Sinn Féin and Mr Finian McGrath (Independent). A spokeswoman for the Colombian embassy in London said they had no knowledge of the alleged incident.
The trial of Mr James Monaghan (56), Mr Martin McCauley (40) and Mr Niall Connolly (36), who are charged with training FARC rebels in bomb-making and with using false passports, resumes on February 5th next year.