The Judge hearing the case taken by the PSNI to try to compel a Sunday Tribune journalist to hand over her notes linked to articles on the Real IRA, will give his verdict next week.
The paper's Northern Editor Suzanne Breen received a phonecall from the Real IRA claiming responsibility for the murder of two British soldiers in Antrim last March.
Police investigating the attack at Massereene Barracks are seeking the journalist's notes as part of their enquiry.
However, Ms Breen says to do so would be to breach her profession's code of ethics and would put her own life, and that of her partner and child, in danger.
At a hearing at Belfast High Court today, Suzanne Breen and Sunday Tribune Editor Noirin Hegarty told Recorder Tom Burgess that journalists were obliged to observe the NUJ's Code of Conduct.
In addition, media commentator Roy Greenslade, Channel 4's Alex Thompson and the BBC's John Ware all gave evidence on the importance of confidentiality of sources and the consequences of breaching that confidentiality.