There was about £70 million in Ansbacher accounts in Guinness Mahon & Co in London in the late 1980s and £25 million in Dublin in 1984, the tribunal heard.
Reading from a statement by Ms Sandra Kells, financial director of Guinness & Mahon, Dublin, Mr John Coughlan SC, for the tribunal, said Dublin had two wholly owned subsidiaries in the Channel Islands, Guinness Mahon Jersey Trust and Guinness Mahon Channel Islands, Guernsey, with its subsidiary, College Trustees Ltd, in Guernsey.
Ms Kells said Irish residents placing money offshore in the 1970s may have placed it with College Trustees, or Guinness Mahon Cayman Trust.
Dealing with the Ansbacher payments, in November 1979 Cayman had £4.8 million sterling on deposit with Dublin, increasing to £25.1 million sterling by 1984.
Guinness Mahon & Co in London was the parent of Dublin. Cayman also had deposits with London and in 1984 London owned Cayman through a subsidiary. From the records of Dublin, it was clear Irish companies borrowed money from London, secured by deposits placed by Cayman with Dublin.
Mr Des Traynor was a director of Dublin from 1969 to 1986 and left because a large commercial loan went wrong. He was also chairman of Cayman and represented it in Ireland.
In 1976 he opened accounts with Dublin in the names of Amiens Investments Ltd, Amiens Securities Ltd, Desmond Traynor S Account, and Desmond Traynor SS Account for the operations of Cayman and subsidiaries in the Channel Islands.
Mr Traynor lodged Irish residents' money to the accounts in Irish money, credited with the lodgment in Cayman or in the Channel Islands. He then paid money out of these accounts to other Irish residents as requested.
"It's the `switch'," Mr Coughlan said. It was "attempting to get around the exchange control requirements".
Irish residents could deposit or withdraw Irish pounds in Dublin and get interest on the money without exchange control clearance or informing the Revenue Commissioners.
The Amiens accounts operated until 1990. From them money was paid in the first instance to Haughey Boland to meet Mr Charles Haughey's expenses.