Bertie Ahern has told the Mahon Tribunal today that some of the sterling lodgements made to his accounts in the early 1990s were winnings from bets on horses.
Mr Ahern was being quizzed at Dublin Castle today about the source of his finances.
It was his first time in the witness box since stepping down as Taoiseach.
Mr Ahern told the Tribunal that it is the height of absurdity to suggest that he knowingly concealed sterling lodgements or knowingly gave misleading answers.
He claims the lodgements were money he had saved from his salary.
Mr Ahern said this money was exchanged for sterling with his friend businessman Tim Kilroe with the intention of investing in an apartment in the UK.
The investment didn't go ahead and Mr Ahern said that while he doesn't recall lodging the money to his building society accounts in Drumcondra he accepts that he must have.
Mr Ahern also claimed that some of the lodgements were winnings from sporting bets, saying he has a clear recollection of a few good wins on horses over the years.
Earlier the former Taoiseach accused the Tribunal of trying to hang his former secretary Grainne Carruth when she appeared at the hearing in March.
Bertie Ahern is back in the witness box tomorrow morning.