Developer Tom Gilmartin has accused Taoiseach Bertie Ahern and "a long line of ministers" of committing perjury at the Mahon tribunal.
He told the tribunal yesterday Mr Ahern was a "peasant liar" and "the biggest conman this country has ever seen".
Colm Ó hOisín SC, counsel for Mr Ahern, accused Mr Gilmartin of doctoring entries in a notebook that recorded a meeting he said he had in Dáil Éireann with Government ministers, including Mr Ahern.
Mr Gilmartin had told the tribunal that Cork developer Owen O'Callaghan told him he had given Mr Ahern up to £80,000 (€101,000) in connection with his development of the Liffey Valley shopping centre at Quarryvale.
He had also given evidence that he met the late Liam Lawlor on February 1st, 1989, in Buswells Hotel and Mr Lawlor brought him to Leinster House.
He was brought into a room with a rectangular table and was introduced to a number of ministers including the late Charles Haughey, Albert Reynolds, Séamus Brennan, Pádraig Flynn, the late Brian Lenihan, Bertie Ahern and Mary O'Rourke, he said.
Afterwards, outside the meeting, he was approached by a stranger who told him he would make a lot of money out of developments in Ireland and should lodge £5 million to a bank account in the Isle of Man.
Mr Ó hOisín said it could be proved that Mr Ahern was presenting certificates in Glasnevin at the time and was not at that meeting. He said Mr Ahern believed he may have been introduced to Mr Gilmartin, but at a completely different stage.
He questioned why Mr Gilmartin had not mentioned that Mr Ahern was present when he spoke to his solicitor, Noel Smyth, in May 1998.
Mr Gilmartin said Mary O'Rourke had agreed there was a meeting and that Mr Ahern was at it. "We know Mr Ahern wasn't present," Mr Ó hOisín said. "You doctored this notebook, wrote in all of this fictitious detail well after the event."
"It is not my diary is doctored," Mr Gilmartin said.
He said he had witnessed "one minister after another" coming in to the tribunal and perjuring themselves, including Mr Ahern.
He also accused Mr Ahern of being a "total peasant liar".
"He's the biggest conman this country has ever seen, he pales Charlie Haughey into the ha'penny place."
Mr Ó hOisín asked Mr Gilmartin about the timing of various pieces of information he had given the tribunal about Mr Ahern. He asked why some things were initially omitted and then disclosed to the tribunal at later stages. Mr Gilmartin said he was reasonably certain he had passed on all his information.
"We are asked to prefer your recollection now to notes taken, contemporaneous notes taken by diligent counsel," Mr Ó hOisín said. He said Mr Gilmartin was "stretching credulity to breaking point" and spicing up stories about Mr Ahern.
Mr Gilmartin said he didn't invent stories. "You couldn't in a million years invent my experience in Dublin, it would take a genius to invent it," he said.
"I certainly don't underestimate your ability to invent stories," Mr Ó hOisín said.
Mr Gilmartin claimed that before the last election, Mr Ahern had a meeting with Sir Anthony O'Reilly of Independent News and Media and since then, "all we are reading are the thoughts of chairman Mao".
Closing his cross-examination, Mr Ó hOisín accused Mr Gilmartin of allowing himself to be used as a conduit for malicious gossip. "People were very able to play on the paranoia that is very much part of your make-up," he said.
