Tribunal chairman Alan Mahon has asked counsel for the Taoiseach to produce details of what Mr Ahern's legal team says are 67 different possible combinations of calculations based on remittances from bank branches to AIB's currency services department on December 7th, 1994.
Mr Mahon said today the tribunal had written to Mr Ahern's lawyers in early August after they put certain hypothetical calculations to AIB foreign exchange expert Rosemary Murtagh during their cross-examination at the tribunal in July.
Both the tribunal and Mr Ahern's legal team are trying to work out the breakdown of a lodgement made by Mr Ahern's then-partner Celia Larkin to AIB in O'Connell St, Dublin, in December 1994.
It appeared Mr Ahern's lawyers had "declined" to furnish the calculations put to Ms Murtagh to the tribunal, Mr Mahon said today.
Ms Murtagh is being cross-examined by Mr Ahern's lawyers.
Counsel for Mr Ahern Colm Ó hOisín said he was not saying the calculations would not be provided "in due course". But he said Ms Murtagh was being asked to take the calculations put to her at "face value" in the same way as she had been asked to accept calculations of different transactions put to her by the tribunal's own lawyers.
He said the position of AIB had "modified somewhat" since July, and "we are entitled to hear the evidence from the witness and to see exactly what that evidence is" before those calculations were furnished.
AIB's lawyers wrote to the tribunal in August to clarify certain issues raised in the testimony of Ms Murtagh in July.
Mr Mahon said he did not want to be "playing games" with Mr Ahern's lawyers. "We wanted to see the calculations and we want to see them as soon as possible," he said. "It seems to me to be ridiculous to suggest that we should not see them and that we should not see them in the immediate future."
The tribunal contends that the sum of £28,772.90 lodged by Ms Larkin on December 5th 1994 is the equivalent of €45,000. Mr Ahern says it was not dollars and that the lodgment was a sum of £30,000 sterling.