Angry exchanges erupted at the rail signalling inquiry yesterday when Esat founder, Mr Denis O'Brien, questioned the ability of Mr Sean Doherty TD to lead the investigation.
Mr O'Brien said Mr Doherty was unfit to be chairman given his past involvement in phone-tapping - a reference to his bugging of two journalists' telephones while minister for justice in 1982.
The former Esat chief executive repeated the claims when offered the chance to withdraw them and emphasised his criticism was of Mr Doherty personally and not the inquiry sub-committee.
"What I said was I did not think you are a capable chairman of this committee given your involvement in the past in phone-tapping and your involvement in other matters," said Mr O'Brien.
He also accused the chairman of "abusing" other witnesses and demanded that Mr Doherty "treat people with respect".
Mr O'Brien's initial outburst came 10 minutes into his second day of evidence to the subcommittee which is inquiring into a £36 million overrun in a £14 million rail signalling system which was supposed to be in place two years ago but is still not finished.
It has been suggested that an attempt to lay cables along the railway lines for Esat's fledgling telephone network added to the delays and costs of the signalling system. It has also been suggested the deal was more in Esat's favour than CI╔'s.
Mr O'Brien was being questioned about Esat's deal with CI╔ when his associate, Mr Leslie Buckley, a former consultant to CI╔ who went on to become a director of Esat, asked to be allowed help Mr O'Brien give details of the negotiations.
Mr Buckley persisted in speaking to Mr O'Brien after being told he could not and a row followed in which Mr Doherty accused Mr Buckley of interfering.
Mr O'Brien intervened, making the remarks about Mr Doherty's phone-tapping past. A committee member, Mr Noel O'Flynn, said the remarks were "outrageous" but Mr O'Brien repeated them when called on to withdraw them.
Mr Doherty also said the remarks were outrageous. "It makes a statement about you, not me," he told Mr O'Brien.
Questioning resumed temporarily but a further row broke out when Mr O'Flynn asked if Mr O'Brien had involved the Department of Public Enterprise in his negotiations with CI╔, adding that it was "not a trick question".
Mr O'Brien replied that other witnesses had been asked trick questions and became annoyed when Mr O'Flynn stated he would treat Mr O'Brien like a gentlemen.
Mr O'Brien, who lives in Portugal, said he had been summonsed to give evidence on Tuesday but his appearance was cancelled with too little warning. "That's no way to treat anybody," he said.
He had earlier complained that a list of over 120 witnesses to be called before the inquiry had been released to the press with his name placed first.
After a short adjournment, Mr Doherty stated he was giving Mr O'Brien an opportunity to withdraw the "allegations against the committee" that he had made earlier but Mr O'Brien refused.
Mr Doherty said he was excusing Mr O'Brien, Mr Buckley and a third witness, former Esat executive, Ms SinΘad O'Marcaigh, from the session "for the moment". All three are expected to recalled in the next week.