Former AIB chairman Peter Sutherland flew to a crisis meeting in the Vatican last July as Pope Francis, sought to deal with the financial scandals that have hit the Catholic Church.
Sutherland addressed the Council of Cardinals, the most senior advisers to the Papacy, in a room close to Doma Santa Marta, the Pope's residence.
Sutherland, an unpaid financial adviser to the Vatican, is understood to have pressed for the church to change its ways.
'Transparency is important and necessary' is said to have been the theme of his briefing. Sutherland, chairman of Goldman Sachs international, was appointed as an adviser to the Administration of the Patrimony of the Apostolic See, an asset manager for the Vatican.
Pope Francis has ordered a major reform of the Vatican's banking and financial systems after a series of scandals have emerged in recent months.