Appearing before the tribunal was "very unpleasant task" and he had not volunteered to become involved, Mr Mark FitzGerald told the tribunal.
Mr Roderic O'Hanlon SC, for Mr Michael Lowry, asked Mr FitzGerald to explain why his statements to the tribunal, made late last year, were at such a remove from the events outlined in them, which relate to the mid-1990s.
Mr FitzGerald said he got a letter from the tribunal, came in to Dublin Castle and was asked questions. He told Mr O'Hanlon he had been aware the matters were of interest to the McCracken and Moriarty tribunals. He had sought advice and was told he was not required to contact the tribunals.
Asked why he did not decide to come forward, despite the advice, Mr FitzGerald said that as a citizen he fulfilled his legal duties but he did not particularly want to volunteer for what was an "unpleasant task". As a son of a politician he would be sensitive to the issues involved and what was happening now was for him a "very unpleasant task".
Mr Eoin McGonigal SC, for Mr Denis O'Brien, said Mr FitzGerald had a unique position in Fine Gael as he was the son of a former Taoiseach, Dr Garret FitzGerald.
He asked Mr FitzGerald about his fund-raising activities. He said he was more in "the retail end of the fund-raising spectrum" and did not consider himself to have been a significant fund-raiser, as suggested by Mr McGonigal. He was in favour of dialogue between politics and business and with business people getting involved in politics.
When Mr McGonigal said Ireland was a small place and politicians and business people had to come into contact, Mr FitzGerald said he was in favour of State funding of politics.
Mr McGonigal said when Fine Gael went into government in December 1994, the natural reaction of business was to become involved with the party as it had not been involved in government for some time. Mr FitzGerald said he had no problem with people having access to politicians and thought it was a good thing. He believed a lot of politicians knew very little about business.
Mr FitzGerald said he did not have an issue with Mr O'Brien becoming involved in a Fine Gael golf classic in October 1995. His concern was with Mr O'Brien becoming involved in a series of Fine Gael fund-raising events in the context of his seeking a mobile phone licence from the government. It was for this reason that he mentioned it to the then newly appointed general secretary of Fine Gael, Mr Jim Miley.
Mr FitzGerald has told the tribunal that he met Mr O'Brien twice during October 1995 and Mr O'Brien raised the licence competition. Mr O'Brien, in a statement of intended evidence, has disputed the evidence.
Mr Gordon Gill of Sherry FitzGerald auctioneers told Ms Jacqueline O'Brien, for the tribunal, of acting as arbitrator in a rent dispute concerning an office block, Marlborough House, off O'Connell Street, Dublin. The building had been bought by Mr Ben Dunne who was seeking a rent increase from the tenant, Telecom Éireann.
In June 1995, after the arbitration, he was told by Mr FitzGerald of the approach that had been made by Mr Lowry on behalf of Mr Dunne. He could not recall the detail but he could recall being "a bit shocked". He was told Mr Lowry had approached Mr FitzGerald in an attempt to influence Mr Gill in favour of Mr Dunne.
He inferred that what was involved was the granting of a higher rent. He had formed the impression that Mr FitzGerald was "a bit shocked and a bit disappointed" as a result of the approach.
A new witness is to give evidence tomorrow.
