Ruling in O'Brien case after Christmas
The High Court has reserved judgment in the case brought by businessman Denis O'Brien against the State and a Dáil committee.
Ms Justice Úna Ní Raifeartaigh said she would deliver her ruling on the legal action after Christmas.
Arguments for both sides in the case concluded yesterday, after a seven-day hearing.
Mr O'Brien had claimed the outcome of proceedings he brought against RTÉ last year was effectively decided by remarks made by TDs in the Dáil, which disclosed details of his personal banking affairs.
His lawyers maintained statements made by Social Democrats TD Catherine Murphy and Sinn Féin TD Pearse Doherty breached his rights and the separation of the powers of the Oireachtas and the courts.
He brought the case against the State, the Clerk of the Dáil and the Dáil Committee on Procedure and Privileges.
Lawyers for the defendants argued that statements made by TDs in the Dáil were protected by parliamentary privilege under the Constitution.
They contended the courts had no jurisdiction to intervene in the process of the freedom of speech in the Oireachtas.
Mr O'Brien was the only witness to give evidence.
Eileen Barrington SC, for Mr O'Brien, said there had been "a deliberate and knowing undoing, not just of a court order but of the proceedings because proceedings were in effect determined."