An AIB official has told the Mahon Tribunal he has no recollection of Bertie Ahern buying £30,000 sterling at the O'Connell St branch.
But Philip Murphy, former assistant manager at the branch, said if Mr Ahern said it happened then 'maybe it did happen'.
Mr Ahern has explained two foreign exchange lodgments in 1995 as coming from the result of a purchase of £30,000 sterling from Mr Murphy.
The tribunal says there is no record of this in AIB O'Connell St.
Earlier, the tribunal ruled that lawyers for the Taoiseach will not be able to cross-examine an accountant who drew up a spread sheet on AIB foreign currency transactions.
Judge Alan Mahon said the document drawn up by a forensic accountant was an illustrative tool to deal with possible exchange rates and transfer of funds between AIB O'Connell St and its currency services section.
He said the document did not reach any conclusion and did not constitute evidence.
Gilmartin denies £50,000 bribe
Former developer Tom Gilmartin has denied paying a £50,000 bribe to then Environment Minister Padraig Flynn to get tax breaks for his proposed Quarryvale development.
Mr Gilmartin told the Mahon Tribunal that he would rather live under a bush than be corrupt.
Mr Gilmartin under cross-examination by counsel for rival developer Owen O'Callaghan admitted that tax designation would have been a huge bonus for his Quarryvale development.
But he denied having Mr Flynn 'in his pocket' following the cheque for £50,000 he gave him in 1989.
Mr Gilmartin was asked about a condition of the £8.5m loan he got from AIB in 1990 that stated the bank understood the site would get tax designation.
He replied this was the bank's information. He had received assurances from two or three Ministers on tax designation but it was not necessary for the development.
Mr Gilmartin said he paid the £50,000 as a donation to Fianna Fáil out of desperation because his plans were being thwarted when he refused to pay large sums of money to crooked politicians.
