The judges in a Special Criminal Court murder trial will rule on Tuesday whether certain communications between the chief prosecution witness and his solicitor should be disclosed to the defence.
All sides spent today debating the issue on the 35th day in the trial of the three men accused of murdering dissident republican Peter Butterly last year.
The court heard that David Cullen had agreed to disclose to the defence documents relating to his communications with his solicitor since June 5, 2014.
The State said that this was not a general waiver to his claim to legal professional privilege over their communications.
However, defence lawyers have sought disclosure of all communications between Cullen and his solicitor and the court spent much of today and yesterday hearing legal submissions on the issue.
Cullen gave evidence in chief in which he implicated the three accused men in the murder of Mr Butterly in the car park of a Meath pub.
The 30-year-old was then cross examined by the defence and this is when he raised the issue of privilege in relation to communications with his solicitor.
He refused to answer questions relating to the issue and told the court that he wanted to speak to his solicitor before answering any more questions from the defence. The court at first refused, but then acceded to his request.
Peter Butterly was shot dead in the car park of the Huntsman Inn, Gormanston, Co Meath on March 6 2013.
Dean Evans (aged 24), of Grange Park Rise, Raheny, Edward McGrath (aged 33) of Land Dale Lawns, Springfield Tallaght and Sharif Kelly (aged 44), of Pinewood Green Road, Balbriggan have pleaded not guilty to murdering the 35-year-old father-of-two.
Mr Evans and Mr McGrath have also pleaded not guilty to firearm offences on the same occasion.
Cullen, who is currently serving a three-and-half-year prison sentence, was allegedly "part of the murder plan himself" but turned State's witness earlier this year.
The three-judge, non-jury court will consider its ruling on the disclosure issue over the weekend.