Dessie O'Hare, the man known as the "Border Fox", has been transferred out of Portlaoise Prison to Castlerea Jail, in preparation for his release.
O'Hare is serving a 40-year sentence for the abduction and mutilation of Dublin dentist, John O'Grady in 1987.
O'Grady was kidnapped and held for a substantial ransom, during which O'Hare chopped off his finger.
In April 2001, lawyers for O'Hare took a High Court action to have him released under the terms of the Good Friday Agreement, as O'Hare was a member of the INLA.
Two of O'Hare's gang have already been freed.
It has now been confirmed that his transfer from Portlaoise to Castlerea Jail is in preparation for his own release, having served just 15 years of the 40 years sentence.
An exact date for his release has not been disclosed.