The octogenarian, whose revelations about planning corruption involving former minister Ray Burke were instrumental in setting up the inquiry, died peacefully at Beaumont Hospital after a long illness.
Given his central role in implicating Mr Burke and several other wealthy businessmen in corruption, Mr Gogarty, 88, would have been a crucial witness in any prosecution.
However, the DPP has to date given no indication that any charges are likely to be brought as a result of the findings of the tribunal.
In a landmark report published in September 2002, its chairman, Mr Justice Feargus Flood, concluded Mr Burke had received a series of corrupt payments totalling over £250,000 related to planning matters from a number of developers.
Neither has any party faced a charge of obstructing the tribunal, despite Mr Justice Flood's findings that more than a dozen individuals including Mr Burke had impeded its work.
Mr Burke was jailed for six months for tax offences earlier this year, while George Redmond was also imprisoned although his conviction for corruption was subsequently overturned by the Court of Criminal Appeal.
However, neither case was related to the central evidence of Mr Gogarty at the tribunal.
"The lack of any prosecution is probably an indication of the difficulty faced in securing a conviction for corruption, especially as evidence given to a tribunal cannot be used in any subsequent trial," said one senior barrister yesterday.
"Mr Gogarty would have been an important witness if any case ever got to court. His death makes the likelihood of any criminal prosecution now going ahead very remote," he added.
Mr Gogarty is survived by his wife, Anna, and seven children including son Eamon, who regularly accompanied his father during his evidence to the tribunal.
Since his last appearance in the witness box at Dublin Castle on July 5, 2000, he has deliberately refrained from commenting on subsequent developments at the tribunal, as well as turning down all requests for interviews.
However, he indicated through a family member three years ago that he was pleased with the findings of the tribunal which fully accepted his controversial evidence to the inquiry.
Last June, Mr Gogarty was awarded his full legal costs of around e3.5m by the current tribunal chairman Judge Alan Mahon.
Meanwhile, the tribunal's former chairman, Mr Justice Feargus Flood, yesterday described Mr Gogarty as "a remarkable man for his age".
The retired judge who stepped down from being sole member of the inquiry in 2003 said its most famous witness was "a character with a wonderful humour".
However, he acknowledged not everyone would necessarily share the same opinion of the former company director. "People have different views about him. I don't wish to be either laudatory or critical of him. We had our problems together, but I will remember him with a great deal of affection," he said.
"In some 47 years of being a barrister and a judge, it's fair to say that he was the most outstanding witness I encountered," said the judge, who was also involved in some high-profile and controversial extradition and rape cases during his career on the bench.
He admitted that when recounting the six years spent chairing the tribunal that he would hold "affectionate memories" of his famous witness. The judge said he had only ever met Mr Gogarty for five minutes before his appearances in the witness box at Dublin Castle in 1999.
"I am trying to tell the truth - warts and all." -
"Burke could go into the Dáil and slander me and tell lies, and Bertie Ahern and Dermot Ahern could hold kangaroo courts on me. Sorry, my Lord, they didn't come to me, they went up the trees in north Dublin." -
"The truth is stranger than fiction." -
"Bring Bertie Ahern in ... as well as every tree in Dublin." -
"It'll all come out in the washing." -
"From the dock? Put in the dock, that's where they want me - in the dock. Oh Jesus, Oh Mother of God." -
"I'm not. I'm looking at you. I've a pain in my face looking at you." -
"Sure yourself and Cooney are the mothers of invention" -
"I reject your conceptions ... immaculate or not." -
"What am I going to do for an hour?" -
"The truth is out there. Just like in that famous song: the answer is flowing in the wind." -
"Your nose is nearly covered with your bloody moustache and your beard." -