Real IRA terrorist Michael McKevitt has been taking drama, creative writing and yoga classes in prison, a court has heard.
The 65-year-old has been granted leave to bring fresh legal proceedings aimed at securing his early release from jail.
Yesterday, McKevitt, from Beech Park, Blackrock, Co Louth withdrew a legal challenge against the Minister for Justice's refusal to release him under a scheme of enhanced remission of sentence.
However, he will now use another legal mechanism, judicial review, to contest his continued detention.
McKevitt was jailed for 20 years in 2003 for directing terrorism and membership of an illegal organisation the Real IRA. His sentence was backdated to 2001.
He claimed that under 2007 prison rules he should already be a free man.
His application is brought on grounds including those that he has been a model prisoner and has engaged in a number of activities in the prison.
The activities include courses in computing, web design, speech and drama, art, French and yoga. He has also completed a course offered by the Open University in creative writing.
In light of a recent Supreme Court case, McKevitt withdrew an application to be released under Article 40 of the Constitution. Despite the withdrawal, Mr Justice Bernard Barton gave his judgment, which he said he was giving in light of the public interest in the case, and stated that McKevitt was being detained on what was a valid warrant.
However, McKevitt then secured permission from Mr Justice Kevin Cross to have the High Court conduct a judicial review of the Justice Minister's decision instead.
In the proceedings, the terrorist, represented by Mark Lynam Bl, is seeking declarations that the minister based her decision on irrelevant and unlawful considerations. He also wants a declaration the decision is disproportionate and unreasonable.
His lawyers claimed the Minister for Justice did not give proper consideration for a one-third reduction in his sentence for good behaviour and for engaging in structured activities in the prison.
McKevitt claims that the minister took into consideration improper material, including a report from the Garda Siochana that he was likely to re-offend.
Among McKevitt's arguments is that before making her decision the minister was informed that he is a spokesperson for a paramilitary organisation.
This he says is "factually incorrect" and he acts as a spokesperson for Republican Prisoners on E2 wing of Portlaoise prison in their day to day dealings with the prison staff.
It is accepted McKevitt remains a committed republican.
McKevitt, who has held the status of enhanced prisoner since 2012, has been a model prisoner, the court heard.
He only received disciplinary sanctions on two occasions, in 2004 and 2001, when the entire prison population was collectively punished.
He has been granted temporary release twice during his incarceration and no issue arose from those incidents. He is due to be released in March 2016. The application, which state lawyers intend to oppose, was adjourned till early October.