A husband and wife were still being questioned by police in Northern Ireland today about the Omagh bomb atrocity.
A decision on whether to release or charge them could be known tomorrow.
The man has been questioned before by the PSNI about the bombing - the single worst atrocity in the 30 year history of terrorist violence in Northern Ireland.
The couple were being held in Gough Barracks in Armagh city and were also being questioned about a series of other attacks carried out by dissident republicans opposed to the peace process.
These include bombings in Lisburn, Co Antrim, and Newry and Banbridge, Co Down, which came before the Omagh attack which killed 29 people including the mother of unborn twins and injured more than 200 others.
Officers probing the Omagh bombing ordered the couple's detention after widening their inquiries in a bid to bring the killers to justice.
Up to 200 police and troops were involved in a major security swoop to seize the couple at a house in Jonesborough, south Armagh.
Senior security sources confirmed the arrests represented a significant breakthrough in the five-year hunt.
It is understood the arrests were linked to one of the cars which is thought have been used at the time the 500lb bomb was transported through the west Tyrone countryside before being abandoned.