Luton-based developer Tom Gilmartin today told the Mahon tribunal that he "absolutely refused" to pay corrupt payments to anyone.
He said: "I refused to be involved in corruption - even if it cost me - and it did cost me".
The tribunal heard evidence today from Mr Gilmartin about his plans to develop the Quarryvale site in the late 80s and early 90s and he was pressed by counsel for the tribunal on an allegation that he was asked for half a million pounds by former Dublin councillor Joe Burke.
The Quarryvale Two module of the tribunal is looking at the events surrounding the rezoning of lands that eventually became the Liffey Valley Shopping Centre.
Mr Gilmartin said he had identified Quarryvale as "one of the best sites in the Dublin area" for a developer. He said, however, he "did not pursue very vigorously" the question of getting special tax designation for the site at the time, because "the state of the country" economically at that time in the 1980s.
The issue had been "suggested" but was "more or less ruled out by the government" because it would have been "very contentious". Secondly, it would have shown preferential treatment to one developer over another he said.
Mr Gilmartin also said he had not raised the possibility of his being given special tax designation to back up an application for a credit facility with IIB bank as a "lever to get money".
During the hearing today Mr Gilmartin was questioned on his allegation that former Fianna Fáil Dublin city councillor and friend of the Taoiseach, Joe Burke had demanded IR£500,000 at a meeting sometime in the autumn of 1989 after his tender for council lands at Irishtown was accepted.
He said today in relation to the alleged request for money, that Mr Burke had "talked around the surface rather than getting to the point of it" but that "it meant the same thing".
Mr Burke had, after that meeting, offered to drive him to the airport and asked him if he would meet Mr Ahern, who was then Minister for Labour Affairs, on the way.
Mr Gilmartin said Mr Burke had stopped at two different pubs on the way to the airport and had come back out, but that Mr Ahern was not there. Eventually, Mr Gilmartin said he insisted on being driven to the airport as he was late for his flight.
Tribunal counsel Pat Quinn SC put it to Mr Gilmartin that it was a "most startling" allegation that he would not have forgotten to mention in his 1999 statement to the tribunal.
In a statement made to the tribunal in March 2004, Mr Gilmartin said: "Burke asked me would I not be prepared to pay half a million because I knew Bertie Ahern was looking after me."
However, in earlier statements Mr Gilmartin says Mr Burke "never specifically asked for anything and neither did I take the bait".
Mr Gilmartin said today he had not read the earlier statement taken by his solicitor and had not had a chance to proof-read it before it was sent to the tribunal.
Mr Quinn asked Mr Gilmartin if he was saying that the only thing that was not clear in relation to the alleged request by Mr Burke for a half million pounds was whether he was asking for it for himself or with Mr Ahern's authority.
"That's correct," Mr Gilmartin said.
Pressed on why he was only at this later stage raising the alleged request for money, Mr Gilmartin said it was not put to him as a "demand" but it was put to him in what he would call "Donegal fashion", with Mr Burke talking "around and around" the half a million.
Mr Gilmartin said that when he told Mr Burke during the meeting he would "give half a million" just to get out and "get my money back", Mr Burke had asked: "Would you?", he said.
Mr Burke was sent by the Taoiseach to meet Mr Gilmartin after the developer complained to Mr Ahern, who was then minister for labour, of difficulties with the proposed development of Quarryvale.
In previous evidence to the tribunal Mr Ahern, said he has no recollection of discussing Quarryvale with Mr Gilmartin, but accepts he advised him to contact Mr Burke.
Mr Gilmartin admitted today that he was confused over the dates of the meeting with Mr Burke. "I'm no good on dates - I always said I'm terrible on dates," he said.
The Quarryvale Two module is scheduled to last at least six months and involves almost 80 witnesses. Much of the evidence given by Mr Gilmartin today has previously been aired during the Quarryvale One module.
Mr Gilmartin was also asked this morning by counsel for the tribunal Pat Quinn SC whether he had disclosed to any person other than his solicitor the documents circulated by the tribunal.
Mr Quinn said the tribunal would now put this to all witnesses.
Mr Gilmartin said he had not done so and that, in fact, journalists had telephoned him days before he had seen the documents relating to the current module.
Tribunal chairman Mr Justice Alan Mahon said the tribunal had taken all possible steps to prevent leaks of its documentation to the media, including taking legal against two newspapers.
However, he said a Supreme Court decision "severely limits" the tribunal's right to take injunctive relief in relation to such matters.
The chairman was responding to an attack yesterday by counsel for Taoiseach Bertie Ahern, Conor Maguire SC, who said the circulation of documents in relation to Mr Ahern's affairs at the time when a general election was imminent created a "serious risk of an interference with the democratic process".
Judge Mahon said he "absolutely and categorically" rejected any such suggestions and said the tribunal was an independent body.
Co-chairman of the tribunal Judge Gerald Keyes told Mr Maguire that he would have "full and limitless opportunity" to cross examine Mr Gilmartin in relation to the Quarryvale One evidence and in relation to any new evidence he gives.