All of the Colombia Three, who were interviewed by detectives in Dublin after the trio secretly returned to Ireland, have been freed.
Martin McCauley was interviewed at Kilmainham garda station
Niall Connolly was released without charge at about 0000 BST. It is believed he had been questioned about alleged passport offences.
Martin McCauley and James Monaghan earlier left police stations in Dublin.
The trio are wanted in Colombia where they have been sentenced to 17 years in jail for training Marxist rebels.
The men had presented themselves at garda stations voluntarily on Thursday.
Niall Connolly was held by police at Harcourt Terrace garda station. Martin McCauley was interviewed at Kilmainham garda station and James Monaghan at Terenure garda station.
They vanished in December 2004 while on bail pending an appeal and have since returned to the Republic of Ireland.
News of their return to the Republic of Ireland broke when Irish state broadcaster RTE interviewed James Monaghan at a secret location on 5 August.
Niall Connolly was interviewed at Harcourt Terrace garda station
It prompted speculation that their return had been part of a deal with the IRA and Sinn Fein, a claim which Taoiseach Bertie Ahern broke off from his holiday to deny.
Colombian vice-president Francisco Santos has said he wants the men extradited but said he did not rule out allowing them to serve their sentences in Ireland.
The trio, who had been accused of being IRA members, were arrested in Bogota in August 2001.
They were found guilty of travelling on false passports in June 2004, but were acquitted of training the Revolutionary Armed Forces of Colombia (Farc).
That decision was reversed after an appeal by the Colombian attorney general and they were sentenced to 17-year terms.