Evidence in the Omagh bombing case is to be re-examined to establish whether there are grounds to retry south Armagh man Sean Hoey.
Mr Hoey was acquitted of a total of 56 criminal charges, including the 29 murders, in Belfast Crown Court two years ago after a marathon trial.
The move comes after two officers accused of lying in the trial were cleared by the Northern Ireland Police Ombudsman.
Assistant Chief Constable Drew Harris told a meeting of the Policing Board that detectives were now looking for 'new evidential opportunities'.
However, he said: ‘Realistically we have to find substantial new evidence if there is any possibility of a criminal prosecution.’
Earlier this week four other men were found responsible for the 1998 bombing in a landmark civil action taken by families of the victims.
In December 2007, Seán Hoey was found not guilty of the bombing and a series of other Real IRA attacks around that time.
In his judgment, trial judge Mr Justice Reg Weir criticised the evidence presented by the prosecution and in particular accused two scene-of-crime officers of misleading the court on material recovered from the scene of a bomb find in a forest in Co Tyrone.
But earlier this year ombudsman Al Hutchinson cleared the officers of a deliberate deception and questioned the defence team's claim that the evidence from Altmore Forest had been wrongly handled.
On the back of these findings, the police have now undertaken a comprehensive review of all the evidence from Altmore and the other Real IRA attacks, including Omagh, to see if a new case can be brought against Hoey.
