The only man jailed over the 1998 Omagh bombing faces a retrial after winning his appeal against the conviction.
Colm Murphy was originally sentenced to 14 years in jail
Colm Murphy, 51, from Dundalk, County Louth, jailed for 14 years in 2002, said his conviction for conspiring to cause the explosion was unsafe.
At Dublin's Court of Criminal Appeal, Mr Justice Nicholas Kearns granted a retrial on two grounds relating to the evidence of detectives at his trial.
The Real IRA blast in the County Tyrone town killed 29 people and unborn twins.
Presumption of innocence
His original trial found he lent his mobile phone and another phone to the gang who planted the Omagh bomb, knowing they would be used for moving bombs.
During that trial, two gardai detectives were accused by a trial judge of consistent perjury in relation to interview notes.
On Friday, the judge said Mr Murphy's appeal against the garda approach to the alteration of interview notes used at his trial, and evidence given by two detectives in relation to them, was to be allowed.
Mr Justice Kearns added that Mr Murphy's appeal against reference to his previous convictions at his original trial was also being allowed.
He said this represented an invasion of his presumption of innocence.
Mr Murphy had appealed against his conviction on 45 grounds, only two of which were accepted.
He was remanded in custody until he can meet bail conditions.
Mr Justice Kearns imposed a requirement of a 50,000 euro (about £35,000) cash deposit and two independent sureties of 35,000 euro (about £21,000).
Twenty-nine people died in Omagh bombing in August 1998
He also ordered that Murphy surrender his passport, report daily to Dundalk Garda station and to provide the address at which he will be residing.
Michael Gallagher, whose son Aiden died in the explosion, expressed "total shock" at the news.
"All the promises made at than time from the Taoiseach Bertie Ahern and the prime minister, nothing seems to have come of that," he said.
He added that the relatives of the dead would keep on working to hold those responsible for the bomb to account.
"It seems to me now that's the number of deaths the people in this country are willing to accept - 31 innocent people including two unborn children, and not one person being held to account for that."
In separate court proceedings, two detective gardai, Liam Donnelly and John Fahy, who are accused of perjury relating to their evidence during Mr Murphy's trial, were served with books of evidence at Dublin District Court on Friday morning.
They are both based in Carrickmacross in Co Monaghan.
It is understood a trial date will be set within the next eight weeks.