A former senior executive at CI╔ remained on the staff of the company when he became a consultant to Esat, the rail signalling inquiry heard.
Dr Ray Byrne, former head of programmes and projects at CI╔, had previously been involved in negotiating a multi-million pound deal allowing Esat to lay telephone cables along CI╔'s rail network.
At the beginning of the inquiry three weeks ago, Dr Byrne gave evidence that he resigned from CI╔ in September 1999 and became an independent consultant.
He said he struck a deal to work as a part-time consultant to CI╔ between September 1999 and July 2000.
He said he also took on consultancy work for Esat during this time but stressed he was contractually free to do so and had the blessing of CI╔.
He said that during the time he was a consultant for both companies, he did not advise Esat on any matters relating to the cable-laying deal.
But CI╔ group solicitor Mr Michael Carroll told the inquiry yesterday Dr Byrne did not leave the employment of CI╔ in September 1999 but merely changed the terms of his employment.
Mr Carroll said Dr Byrne stayed on as a part-time employee until he set himself up as a private company in February 2000.
"He had the status of an employee right up until a date in February 2000," said Mr Carroll, who said he had been involved in the paperwork altering Dr Byrne's terms of employment.
Dr Byrne became a consultant to Esat in November 1999.