The Moriarty Tribunal has heard that a former chairman of the Revenue Commissioners failed to reveal meetings with supermarket businessman Ben Dunne.
Mr Dunne's company was facing a tax bill of almost £39 million.
The chairman, Séamus Páircéir, also became a tax consultant for Mr Dunne following his retirement in 1987.
Mr Páircéir and Mr Dunne held a series of meetings in 1987 following an introduction by then Taoiseach, Charles Haughey.
Lawyer for the inquiry, Jacqueline O'Brien, said when Mr Páircéir was asked why he had not previously revealed these meetings to the McCracken Tribunal he had replied that he did not consider it within its terms of reference.
Mrs O'Brien said the McCracken Tribunal was also unaware that Mr Haughey had received over £300,000 from Dunnes Stores that year.
Dunnes Stores successfully appealed the £39 million tax bill after hiring Mr Páircéir as a consultant on his retirement and paying him £10,000 for his services.
