Liam Campbell is refused bail at High Court in Belfast
A man wanted in Lithuania over allegations he was part of an operation to buy guns and bombs for the Real IRA has been refused bail.
Last week, a court refused to order Liam Campbell's transfer to the Baltic state.
The judge said Campbell was likely to be held in inhuman and degrading conditions if extradited.
Campbell, 49, from Dundalk, was previously held liable for the Omagh bombing.
He was refused bail at the High Court in Belfast on Friday.
The Lithuanian authorities are appealing last week's decision and Campbell will stay in jail until the hearing on Friday next week.
Campbell has been in prison since he was arrested after crossing the border into south Armagh in May 2009.
His lawyers resisted extradition proceedings by arguing that it would breach his human rights.
They brought in a special adviser to the British Home Office and the Council of Europe's Committee for the Prevention of Torture as part of their case.
Prof Rod Morgan visited Lukiskes Prison in Vilnius and delivered a critical assessment of prison regimes in Lithuania.
Campbell's case centred on an argument that extradition would breach his right to freedom from torture, inhuman or degrading treatment or punishment under European law.
Mr Justice Burgess pointed out that reports of human rights violations were not in themselves evidence that a person would be at risk.
The determining factor was whether violations were systemic and the extent to which an individual could be specifically vulnerable to them.
After referring to an earlier judgment that detailed severely overcrowded and unsanitary conditions at Lukiskes Prison, the judge said he was satisfied that extraditing Campbell to Lithuania would expose him to a real risk of inhuman and degrading treatment by reason of the jail conditions.
Campbell's brother Michael was jailed for 12 years by a court in Lithuania in December 2011 after being found guilty of trying to buy weapons for the Real IRA.
The 39-year-old was also convicted of supporting a terrorist group.
Michael Campbell was filmed buying explosives, grenade launchers and rifles from Lithuanian intelligence agents posing as arms dealers.
In June 2009, Liam Campbell was found liable, along with convicted Real IRA leader Michael McKevitt, for the Omagh bombing.
That verdict followed a landmark civil action brought by relatives of some of the 29 people killed in the August 1998 atrocity.
Mr Justice Morgan, now the Lord Chief Justice Sir Declan Morgan, said at the time there was cogent evidence that Liam Campbell was a member of the Real IRA's Army Council.
Two other men originally held responsible, Dundalk-based builder and publican Colm Murphy and Seamus Daly, from Cullaville, County Monaghan, are currently facing a civil retrial after the findings against them were overturned on appeal.