The Ombudsman, Mr Kevin Murphy has stepped down from his position and will be succeeded by journalist and broadcaster, Ms Emily O'Reilly.
As Ombudsman, Mr Murphy's role included adjudicating on disputes over the release of documents under the Freedom of Information Act. And he became embroiled in the ongoing controversy over the proposed to the Act.
He angered Government ministers when he was publicly critical of their appointment of the High Level Group (HLG) of civil servants to assess the impact of the Act since it was implemented five years ago. He said he should have been consulted and published a commentary which went against the HLG's assessment.
But Mr Murphy's resignation is unlikely to be connected to the controversy as he was due to retire last year but agreed to remain in the post until after the second Nice referendum because of his involvement with the Referendum Commission.
In a statement today, Mr Murphy said his decision was made early last year when he had reached the age of 65 and that the Department of Finance had been informally notified.
"My decision was made before the announcement by the Government of proposed amendments to the Freedom of Information legislation and is in no way connected with that issue," he said.
The Minister for Finance, Mr McCreevy today paid tribute to Mr Murphy who had been Ombudsman since 1994, with Information Commissioner added to his ambit in April 1998.
Mr McCreevy said: "significant changes and developments have taken place within the public administration system over the past few years and many of these have been in response to findings and reports he made during the course of his work."
The Minister also announced his intention to ask the Oireachtas MS O'Reill for the post.
Ms O'Reilly has worked as a journalist and political columnist with the now defunct Irish Press, before taking up similar duties at the Sunday Tribune, Magillmagazine, the Sunday Business Postand latterly the Sunday Times. She has also worked as a broadcaster with RTE and Today FM.
Her position must be ratified by the President Mrs McAleese.