Fianna Fail's former national fund-raiser, Mr Paul Kavanagh, was asked by Mr Charles Haughey in 1989 to raise funds for Mr Brian Lenihan's liver operation in the United States, the tribunal heard.
Mr Kavanagh, appearing before the Moriarty tribunal for the first time, said he assumed the money was only to be used to pay for Mr Lenihan's treatment.
He said he contacted several individuals, along with another Fianna Fail fund-raiser, Mr Peter Hanley, in the hope of raising £150,000, but eventually "fell short" of that figure.
Mr Kavanagh said that at the time he was collecting for Mr Lenihan there was also a collection, instigated by Mr Haughey, for a "disabled gentleman" who found himself in an awkward situation.
Mr Kavanagh said the man's story was mentioned in Sunday newspapers last weekend and involved his failure to get some service or benefit.
He told Mr Jerry Healy SC, for the tribunal, he could not remember the exact amount collected for this man. "My recollection was it was either £14,000 or £17,000, but I can't remember for sure."
Referring to the collection for Mr Lenihan, he said Mr Haughey told him "that Brian was in serious trouble and we needed to do something to try and help to get him to the Mayo Clinic for treatment".
"Yes, mind you, we had concentrated the effort of collecting on fairly few people and that was part of the plan, that we didn't want everybody around Dublin or newspapers knowing what we were doing at the time," he said.
Asked how he selected the potential donors, Mr Kavanagh replied: "I think myself and Peter Hanley sat down and we had been continually fund-raising for about eight years. You build up a certain relationship with some people that you trust, and also know there would be support for something like that," he said.
Referring to his dealings with Mr Haughey in this period, Mr Kavanagh said: "I was also on the strategy committee at the time. I was also on the election committee which met every day, and also on three or four State boards. He put me on one or two to report back to him on certain companies having difficulty at the time."
He said: "We had a figure in mind at the time of trying to raise about £150,000, but my recollection is we fell short of it."
Mr Healy asked if that target was arrived at after consultation with Mr Haughey.
"I think I asked him what sort of money are we talking about . . . what is this sort of thing going to cost . . and from recollection a total figure of £200,000 seemed to be the figure that the Mayo Clinic was going to cost," said Mr Kavanagh.
"And I am not sure, remembering back, whether I made a provision for the fact that we would probably get money from the VHI or not, and probably not at the time, but the figure we had in mind was around £150,000 . . . was our aim." He said he subsequently passed on the names of the donors to Mr Lenihan.
Asked what Mr Haughey's role was, Mr Kavanagh said: "Mr Haughey always did everything in a sort of structured way in terms of `go and do your best to raise money and whatever money you raise bring in to Eileen Foy'." Ms Foy was Mr Haughey's personal secretary.
"I remember at the time she would acknowledge receipt of any cheques she got, and she was the person to whom the cheques were sent. In fact, I often dropped into the office and handed them to her," said Mr Kavanagh.