Taoiseach Bertie Ahern has been asked to explain why he only told the Mahon tribunal in an interview earlier this year that he had purchased the sum of £30,000 sterling in 1995.
Mr Ahern says he bought that amount with some of the £50,000 withdrawn from the account in former partner Celia Larkin's name in January 1995.
However, the tribunal has not been able to find a record of such a purchase of sterling at that time in early 1995.
Des O'Neill SC, for the tribunal, asked Mr Ahern what it was that triggered his recollection of having bought such a sum, when he had not previously disclosed it to the tribunal.
Mr Ahern insisted he had no exact recollection of buying the sum but that it had always been in the back of his mind that he had bought a large sum of sterling.
"The fact that it was foreign currency or not, it made no difference to me at that stage," he said today. He had bought it with the intention of either giving it back to Michael Wall, who "operated in sterling," or making it available to Mr Wall to carry out the work on the Beresford house in Drumcondra himself.
The house, the tribunal has heard, was bought by Mr Wall who then rented it to Mr Ahern and later sold it to him.
Mr Wall said he handed over a sum of about £28,000 sterling in Mr Ahern's constituency office on the day after a fundraising dinner for Fianna Fáil in December 1994.
The money was intended for use on refurbishing the house, both Mr Ahern and Mr Wall have said. It was lodged to an account opened in the name of Ms Larkin, for Mr Ahern's benefit, on December 5th 1994.
Mr Ahern said today that in the end he hadn't given the £30,000 he had purchased in 1995 to Mr Wall as the Manchester businessman had "had an accident" and they proceeded with the original arrangement with regard to renting the house in Drumcondra.
He told the tribunal in a lengthy oral statement before his evidence last Thursday that he had changed his mind about the arrangement with Mr Wall and had decided to look for another house. The Taoiseach had later changed his mind back after Mr Wall's accident.
Chairman of the tribunal Alan Mahon put it to Mr Ahern today that buying the sum of £30,000 sterling would be "a pretty unique event in your life" and that he surely would not have forgotten it.
Mr Ahern told the tribunal he provided the detail he believed the tribunal required. He had focused his attention on trying to establish what was asked of him, which was whether he got money from the developer Owen O'Callaghan, he said.
"That's where my mind was at," Mr Ahern said.
Asked by tribunal judge Gerald Keys whether it was not the case that he would have had to notify a bank in advance that he wanted to buy a sum as large as £30,000 sterling, Mr Ahern agreed this was the case. "I have been trying to track it down," he said.
Mr Ahern said it was very likely he would have been "out around the country" at the time and that he would have asked someone to carry out the transaction on his behalf.
"It was my view that somewhere after I took out the £50,000 that I changed a portion of that either to give back to Mick Wall or to let Mick Wall carry out the work himself," he said.
The Taoiseach again repeated that he had been unable to get any information from the bank with regard to sterling sums lodged to his accounts, including one of £19,142 in December 1995.
Mr Ahern said he always believed this particular amount, the equivalent of £20,000, had been sterling, but the bank had been unable to give him this information because it only had a record of the Irish punt amounts.
Today is Mr Ahern's third day of evidence to the tribunal.