The prosecution in the Omagh bomb trial accepted this morning that there is a question mark over the reliability of two of the main prosecution witnesses.
However, in making such a concession, prosecuting QC Gordon Kerr said that their evidence should be considered within the context of all the Crown evidence, some of which still had to be heard.
Last week, evidence was heard about the earlier discovery of another mortar device in a van at Cappagh in Co Tyrone.
The prosecution is attempting to establish a link with this device, through DNA, to Sean Hoey.
Mr Hoey, 37, from Jonesborough in Co Armagh, is accused of the 29 murders that resulted from the Omagh bombing in August 1998.
During cross examination, Fiona Cooper, a PSNI Scenes of Crime Officer, admitted amending her statement after consulting a colleague, and it also emerged that she failed to wear protective clothing during the operation to recover evidence.
The prosecution also conceded that Philip Marshall, a DCI in the PSNI, accepted he had acted in an improper way in taking statements.
On Friday, the trial judge, Mr Justice Weir, told the prosecution to spend the weekend studying transcripts of the officers' evidence.
When the case resumed this morning, Gordon Kerr, who is leading the prosecution, acknowledged to the judge that the reliability and credibility of the two police witnesses should be treated with caution.
