Colombian officials were last night questioning an Irish tourist over his visa status.
The man, named as Mr Kevin Noel Crena, was being held by immigration officers in the southern Huila province.
His detention comes in the wake of the arrest of three suspected IRA members in the Colombian capital Bogota.
According to news agency reports early this morning, Mr Crena, (37) believed to be from Abbeyleix, Co Laois, is likely to be released after the authorities determined he was a tourist and that his travel documents were in order.
The Department of Foreign Affairs said Colombian immigration authorities had informed the Irish Embassy in Mexico, which has consular responsibility for Colombia, that Mr Crena had been taken into custody and interviewed about his visa status.
Local intelligence sources told Reuters news agency that Mr Crena would probably be released today.
"Everything indicates he was an Irishman visiting Colombia. His passport is valid and he seems to have everything in order. He will likely be released," the source said.
It was reported this morning that state security police planned to put Mr Crena on a plane out of the country by the end of today at the latest. He told reporters he came to Colombia in May on route to Peru and was stopping in guerrilla territory out of curiosity.
Meanwhile, Reuters reported that the three suspected IRA members charged with training Colombian rebels told prosecutors they were visiting Colombia to see the Amazon, write about wildlife and learn Spanish, court documents show.
The men, Mr Niall Terence Connolly, Mr Martin McCauley and Mr James Monaghan, are accused of carrying false passports and of training members of the Revolutionary Armed Forces of Colombia (FARC) to make bombs and other weapons during a five-week stay in a rebel-controlled area.
According to the court documents obtained by Reuters, the three men told prosecutors they never met FARC rebels.
According to the investigation file, forensic tests carried out by the US embassy in Colombia on the men, who were arrested at Bogota airport as they attempted to leave the country on Aug 11th, showed they came in contact with four types of explosives used to make detonators.
The three have denied the charges.
Asked by prosecutors why he visited an area under FARC control, Mr Niall Connolly said he wanted "to see the Amazon as a tourist" and "improve my Spanish".