A senior officer of the Garda Crime and Security Branch said in the Special Criminal Court yesterday that the safety of certain people could be endangered if their identities were disclosed.
Det Supt Philip Kelly claimed privilege in relation to sections of Garda intelligence reports of a surveillance operation carried out in north Co Dublin in January 1998.
The court ruled that two paragraphs in one of the reports should not be disclosed.
Defence lawyers for three men facing explosives charges have been given edited versions of certain intelligence reports, and the court will hear further submissions today in relation to other material.
Det Supt Kelly said the reports contained coded numbers referring to members of the National Surveillance Unit.
A Garda surveillance expert admitted earlier there were "inaccuracies" in an intelligence report about activities at a disused fish shop in Howth, Co Dublin, where explosives were discovered. Det Sgt Oliver Harrington, of the National Surveillance Unit, said he was not the author of the report.
He was being cross-examined on the fifth day of the trial of three men arrested after gardai discovered explosive substances at Howth and in a house at Bettystown, Co Meath. The prosecution has claimed the men co-operated in the movement of the explosives from the house to the fish shop.
Mr Joseph Dillon (55), of Skerries, has pleaded not guilty to possession of an explosive substance with intent to endanger life in Bettystown on January 5th, 1998.
Mr Eamonn Flanagan (45), a native of Co Tyrone with an address in Skerries, and Mr Seamus McLoughlin (69), of Balkill Park, Howth, deny possession of an explosive substance with intent to endanger life or to enable another to do so at West Pier, Howth, on January 5th, 1998.
The men originally went on trial in February 1999 but the trial was aborted due to the illness of one of the judges and a retrial was ordered.