Businessman Michael Wall gave £30,000stg in cash to the Taoiseach's then partner Celia Larkin in December 1994, the Mahon tribunal has been told.
The money was placed by Ms Larkin in an account in her name and was used to fund work on a house in Drumcondra owned at the time by Mr Wall and being rented by Bertie Ahern, the tribunal has been informed. Mr Ahern later purchased the house in 1997.
Information about the matter has been given to the tribunal by Mr Wall, Ms Larkin and Mr Ahern, The Irish Times has confirmed.
The tribunal has examined Mr Ahern's finances as part of its inquiries into an allegation that property developer Owen O'Callaghan gave money to Mr Ahern in the early 1990s as part of the Quarryvale project. Mr Ahern and Mr O'Callaghan have said the allegation is untrue.
The £30,000stg transaction involving Mr Wall was not mentioned publicly in October of last year by Mr Ahern during the so-called Bertiegate controversy.
The tribunal has posted the witnesses it intends calling during the Quarryvale module on its website. The list indicates the tribunal intends hearing evidence about the payments Mr Ahern has said he was given in 1993-1994.
Asked for a comment on the £30,000stg payment from Mr Wall, a spokeswoman for Mr Ahern said he had no comment other than to say he had co-operated fully with the tribunal.
"The Taoiseach did not seek any monies, he received no monies, nor was he offered any monies from Mr O'Callaghan or by anybody connected with him," she said. "He never received money in connection with any tax designation for Quarryvale or anywhere else."
There was no comment from Mr Wall, who was not at home yesterday, and Ms Larkin when contacted said she did not wish to speak to The Irish Times, and hung up the phone.
The tribunal has also been told Mr Wall made a will in 1996 in which he left the Drumcondra house to Mr Ahern in the event of his, Mr Wall's, death. Mr Ahern has told the tribunal he knew nothing of this at the time.