President Michael D Higgins has paid tribute to Frank Murray, the government's representative on the organisation responsible for the finding the remains of The Disappeared, saying "he held the respect of members of the Government right across the political spectrum."
President Higgins said Mr Murray went on to serve the State in a most valuable way.
Taoiseach Leo Varadkar described Mr Murray as "an exceptional public servant".
Mr Varadkar said he wanted to acknowledge Mr Murray's "professionalism and sensitivity he brought to his work over the past number of years at the Independent Commission."
In extending his deepest sympathies to Frank's wife Maureen, to his children Geraldine, Paul, Catherine and Ciara and to his extended family, the Taoiseach said they should take great pride and consolation in Frank's wonderful service to Ireland.
A former secretary general to the taoiseach and the Government, Mr Murray died suddenly yesterday.
Born on Co Leitrim, he joined the Civil Service in 1960. When he retired in 2000, he had served for seven years as secretary general to the Government.
In 2007 he replaced the late John Wilson as the Government's representative on the organisation charged with the search for the remains of the so-called Disappeared.
Kenneth Bloomfield, a former head of the Northern Ireland civil service, worked alongside him in this role. In a statement he said Ireland had lost a great man.
Minister for Justice Charlie Flanagan described Frank Murray as a consummate professional and a perfect gentleman.
The remains of 13 of the Disappeared have been recovered to date.
Frank Murray had been hoping that the bodies of Joe Lynskey, Columba McVeigh and British Army Captain Robert Nairac would also be found.
Former president Mary McAleese said Frank Murray could have gone into retirement after many years service to the state but instead chose to take on the role of Victims' Commissioner.
She said: "He committed himself to that really singularly difficult task of trying to find the disappeared, painstaking work that called for the most endless patience but also endless push, the relentlessness of that patience never to give up and that's what I've always admired about him".
Mrs McAleese said Frank Murray’s death was "just the end of a great, great Irishman".
Former president Mary McAleese says the death of the Victims' Commissioner, Frank Murray is the end of a 'great Irishman' pic.twitter.com/g9O88iC2Ky— RTÉ News (@rtenews) April 1, 2018