The Northern Ireland Police Ombudsman's office has confirmed it is investigating two key prosecution witnesses in the Omagh bomb trial.
Nuala O'Loan was called in by the trial judge to investigate the conduct of forensics officer Fiona Cooper and Det Chief Insp Philip Marshall who took the stand last autumn.
The pair admitted they had "beefed up" their statements to make their evidence appear more substantial.
Seán Hoey, a 37-year-old electrician from Jonesborough, Co Armagh, is denying 56 charges, many of them related to the killing of 29 people, including a woman pregnant with twins, in the Co Tyrone town in August 1998. Two of original charges were dropped last month.
Mr Justice Weir invited Mrs O'Loan to investigate in late October or early November, BBC Northern Ireland reported last night. That was confirmed by the Ombudsman's office. It was also confirmed last night that some of the charges made against Mr Hoey were dropped because there was no case to answer and that this decision was linked to the evidence given by the two police officers.
Central to the prosecution case is the allegation that Mr Hoey made timers for the devices used in Omagh and other bombings of town centres across the North. Forensics evidence has been put before the court in support of this. However, Ms Cooper and Det Chief Insp Marshall admitted they amended their original statements to give the impression that forensic precautions had been taken at the scene of an explosives find when they had not.
Defence barrister Orlando Pownall QC, claimed "their testimony is dishonest" and asked the court for it to be excluded, while Gordon Kerr QC, for the prosecution, told the judge to treat the evidence "with caution".
The prosecution case has concluded and Mr Hoey's defence began this week. He has indicated he will not give evidence. Mr Justice Weir has been strongly critical of the two witnesses and called for inquiries into the amendment of some witness statements and the loss of original documents. He said on November 23rd that this should be carried out "without delay".
The head of the Omagh inquiry, Det Chief Supt Norman Baxter, said he had been in contact with Mrs O'Loan's office but it was felt inappropriate to investigate further while the trial was ongoing.