Independent TD Catherine Murphy yesterday used Dáil privilege to raise issues about businessman Denis O'Brien and his financial arrangements with IBRC.
The arrangements were the subject of a High Court injunction last week.
Mr O'Brien, supported by IBRC, successfully prevented RTE from broadcasting a story by RTÉ’s business editor David Murphy which contained details of loans given to O'Brien by IBRC.
There was no allegation of wrongdoing against Denis O'Brien, but he claimed revelations about his private banking would damage his commercial and banking interests.
Last week's order by Mr Justice Donald Binchy means details of Denis O'Brien's confidential banking arrangements with IBRC cannot be published or broadcast.
Deputy Murphy raised those financial details in the Dáil yesterday under privilege.
O’Brien claimed the information was false and that making such a speech was an abuse of Dáil privilege.
Business Editor with the Sunday Business Post Tom Lyons said: "Under the Constitution, what is said in the Dáil has absolute privilege, and we know that the media reported on things that Mary Lou McDonald has said, and felt safe to do so. In this case, they haven't.
"There is 'absolute' and 'qualified' privilege, and there may be a sense the media only have qualified privilege in this."