Economist Jim O'Leary, who had joined the Department of Finance as a senior advisor in its budget and economic division, has decided to leave the position.
Mr O'Leary said he had left for personal reasons and would now work in a freelance capacity. He was in the position for 15 months and left the Department on good terms.
The economist had worked as a lecturer at NUI Maynooth and also served as a non-executive director of AIB from 2002 to 2008.
Mr O'Leary previously voiced his profound regret for not warning of the dangers of a property collapse while a director of the bank.