Taoiseach Leo Varadkar has paid tribute to former senator Dr Maurice Hayes, who died on Saturday, aged 90.
Dr Hayes was formerly Northern Ireland Ombudsman and was permanent secretary of the department of health and social services. He was also a member of the 21st and 22nd Seanads.
"Dr Hayes was a pivotal figure in Northern Ireland and also made a significant contribution to politics across the island," said Mr Varadkar.
“He helped to change the course of policing in the North through his work with the Patten Commission. As the first Catholic appointed as Ombudsman in Northern Ireland, he helped to bring about lasting change in its society,” he said, adding that his role in the power sharing executive in the 1970s “helped to pave the way” for the Belfast Agreement.
"Dr Hayes took an active role in the politics on this part of the island following his appointment as senator. I also recall his role in Tallaght Hospital reviews, and his wise stewardship as chair of the Forum on Europe.
“Many will also remember Dr Hayes as a committed champion of the Irish language. He made a contribution in so many ways and at so many levels of Irish society,” said Mr Varadkar.
In a statement on Saturday evening, President Michael D Higgins said: "As part of a long and extensive contribution to Irish public life, Maurice Hayes chaired the National Forum on Europe, and his approach was widely praised by all political persuasions.
“He brought a strong commitment to a pluralist and inclusive vision of society to his work in Seanad Éireann and as Ombudsman for Northern Ireland.”
The President said Dr Hayes was a "distinguished" chairman of The Ireland Funds, as well as a "lifelong supporter of sports and the Irish language, and served as a member of the board of directors of Independent News & Media".
“On behalf of the people of Ireland I send my sympathies and condolences to his family and friends,” he said.
Minister for Justice Charlie Flanagan said he was saddened at the passing of Dr Hayes.
“A man of many talents. NI Ombudsman, police reformer, Senator, Chair of Forum on Europe. Down GAA strategist. Always balanced fair and even handed on Northern Ireland matters. Rest in peace,” he tweeted.