Businessman and telecoms entreprenuer Denis O'Brien claims the Moriarty tribunal, which has cost him €12m in legal fees to date, is "out of control" and the procedures it is allowed to use are more akin to those found in a military dictatorship.
O'Brien, who received provisional findings in November, said the tribunal, chaired by Justice Michael Moriarty, is engaged in a "culture of squander" that could ultimately end up costing the taxpayer as much as €200m.
In relation to the findings about himself, O'Brien said: "This is a fight to the end".
O'Brien said he was shocked by recent revelations about one tribunal lawyer submitting an expense claim for Belgian chocolates, but this only highlighted a broader waste of money engaged in by the tribunal.
In an interview with the Sunday Tribune, O'Brien said he had tried to get the Supreme Court and the High Court to make the Moriarty tribunal's procedures and processes fairer, but his attempts were rejected.
He said the tribunal and the courts, where he has taken proceedings in connection with Moriarty, were responsible for a form of rough justice.
"It's unheard of. I mean it's Burma," he told the Sunday Tribune.
It is understood the provisional findings sent to various parties in November are particularly damaging for civil servants who worked under former minister for transport, energy and communications Michael Lowry, when the second GSM mobile phone license was awarded in 1996 to O'Brien's Esat consortium.
O'Brien said since the findings were sent out to the various parties, legal advice, from 1996, from lawyer Richard Nesbitt, which said the awarding of the licence to Esat was legal, had been disclosed.
He said this was a highly significant development and it was now incumbent on Justice Moriarty to admit the tribunal had come up with very little after years of investigation.
"Either Moriarty has the courage of his convictions to say there is no smoking gun here, this is all wrong, we've got it wrong, we are not going to damn anybody, OK, even though we might get slagged off for spending all this time on it – that would be the courageous thing to do, but I don't think he'll do that," said O'Brien.
O'Brien is a significant shareholder in Independent News & Media, the largest single shareholder in the Sunday Tribune.