Northern Ireland's Police Ombudsman has launched an official inquiry into the alleged misconduct of two of the key prosecution witnesses in the trial of the man accused of the Omagh bombing.
Sean Hoey from Jonesborough in south Armagh faces 56 charges including the murders of the 29 people and two unborn babies who died in the Real IRA bombing in Omagh.
During his trial in Belfast, which is still ongoing, two prosecution witnesses, Fiona Cooper a forensic scientist and police officer, Detective Chief Inspector Philip Marshall admitted they had changed their original statements in relation to alleged forensic evidence against Sean Hoey.
Much of the prosecution case is based on forensic evidence.
A lawyer for Mr Hoey accused the witnesses of beefing up their evidence while the trial judge, Mr Justice Weir criticised the witnesses, and said there should be an immediate inquiry.
A spokesman for the Police Ombudsman has confirmed that Nuala O'Loan has begun a full investigation, and her staff are studying court transcripts of all the related evidence.
Its thought that later she may want to speak to the two witnesses and the trial judge.
Yesterday, lawyers for Sean Hoey began the defence case by announcing that the defendant would not be called to give evidence.
It is expected the trial will end this week.
Judgement is likely to be reserved.
