Cork developer Owen O'Callaghan has denied that he was ever asked for £50,000 by Fianna Fáil TD Michael Mulcahy.
Frank Dunlop had privately told the tribunal that Mr O'Callaghan told him Mr Mulcahy asked him for the money in the late 1980s when he was a Dublin councillor, in connection with a project at Cooldrinagh, Dublin.
Mr Dunlop was employed by Mr O'Callaghan to promote the Quarryvale development, now the Liffey Valley Shopping Centre in West Dublin, after Mr O'Callaghan became partners with Luton-based developer Tom Gilmartin in 1991.
The Cooldrinagh project, a retail development close to Lucan, west Dublin, pre-dated the Quarryvale project and was never developed.
Mr Dunlop had told the tribunal in private interview he was not making the accusation against Mr Mulcahy himself.
"I am just telling you what Mr O'Callaghan told me yonks ago,"
Mr O'Callaghan said he did meet Mr Mulcahy in connection with Cooldrinagh, but he thought it was in his capacity as a solicitor.
Tribunal counsel Patricia Dillon SC asked Mr O'Callaghan if he could explain where Mr Dunlop had received his information, if he had not told him.
"I simply can't, from my point of view it's a ridiculous statement," Mr O'Callaghan.
"I am not going to mention names, that's how these things start off."
Ms Dillon said Mr Mulcahy had also vehemently denied the allegation.