A reference to Michael Lowry in relation to the Doncaster property was not disclosed during a case taken in the High Court and Supreme Court by businessman Denis O'Brien, the tribunal heard.
Also, a senior partner with William Fry solicitors decided not to advise Mr O'Brien's father, Denis O'Brien snr, to notify the tribunal about the reference.
Owen O'Connell told John Coughlan SC, for the tribunal, that when he saw a reference to an "ML" in relation to the Doncaster transaction, he recognised it as something that might have implications for the tribunal's inquiries.
He considered his firm "put on notice" when the reference first came to its attention.
The reference was contained in a fax dated August 1999 and which had been sent to William Fry solicitors in 2002 in the course of negotiations with an English firm of solicitors acting for Northern Ireland businessman Kevin Phelan.
William Fry was acting for Denis O'Brien snr and for Westferry, the company that owned the Doncaster property and which was in turn owned by an O'Brien family trust. Mr Phelan had acted in the Doncaster transaction and was claiming he was owed fees.
Mr O'Connell said he discussed the reference with his colleague Owen O'Sullivan and they agreed the firm had been put on notice.
Efforts were then made to establish whether the reference was to Mr Lowry, who has said he has no connection with the Doncaster property.
In the event an explanation was supplied by Mr Phelan's solicitors, in the context of a settlement, to the effect that ML did refer to Mr Lowry but was in relation to "Mansfield" and not "Doncaster" as written in the fax.
Mr Lowry has an acknowledged involvement in the Mansfield property.
Mr Coughlan asked if Mr O'Connell and William Fry had felt they were "off inquiry" as a result of this explanation. Mr O'Connell said he felt "we had gone as far as we could go". He wasn't happy with the explanation "but it was all we were going to get . . . it was at or close to the bare minimum necessary".
He had discussed disclosing the matter to the tribunal with Mr O'Sullivan and they had decided not to do so on their own account. They had also discussed giving advice to Mr O'Brien snr on the matter and had decided against it.
One reason for this was that the firm's advice to Mr O'Brien usually ended up with the tribunal, so the giving of advice in private would in effect have been equal to directing the matter be disclosed.
It was also clear Mr O'Brien did not want that advice. He had never said this but it was "entirely apparent" from the firm's dealings with him.
Also, Mr O'Brien jnr had been adamant that Mr Lowry had no involvement with Doncaster, as had others.
Mr O'Connell said he was not personally involved in the case taken by Mr O'Brien jnr against the decision of the tribunal in 2004 to hold public hearings into the Doncaster issue. He was not a litigation lawyer.
He believed the file in the Phelan/Doncaster matter went to LK Shields solicitors some time in 2003, when it started to act for Mr O'Brien snr.
He was aware, he said, that when seeking injunctions or orders of certiorari, all relevant material must be made available to the court.
He said he had not known that the reference to ML had not been brought to the attention of the court when the 2004 case was taken by Mr O'Brien jnr against the tribunal.
