The death has taken place of the former senator and former Northern Ireland ombudsman, Maurice Hayes.
He died at the age of 90.
Mr Hayes was a major contributor to the Patten Report which reformed policing in Northern Ireland, and led to the creation of the PSNI.
Minister for Foreign Affairs Charlie Flanagan, described him as "always balanced and fair, a man of many talents, NI ombudsman, police reformer, chair of the Forum on Europe and Down GAA strategist."
A native of Killough, Co Down, he was an inter county hurler in the 1940s.
As an innovative and visionary county secretary, he is credited with masterminding Down's rise to prominence in the early 1960s, when they became the first Northern Ireland county to win the All-Ireland football championship.
A graduate of Queen’s University Belfast, he worked as a teacher before becoming Town Clerk of Downpatrick for almost 20 years.
Mr Hayes was the first Catholic to be appointed the Northern Ireland Ombudsman and was Permanent Secretary at the Department of Health and Social Services.
He was a taoiseach’s nominee to the Seanad in 1997 and again in 2002. He had a life-long association with the GAA and was a fluent Irish speaker.
Tributes have been paid to Hayes from across both the sporting and political world this afternoon.
RIP Maurice Hayes, one of the most remarkable minds of the last 50 years. His contribution to transforming @OfficialDownGAA, and Gaelic football by extension, only the tip of his influence on public life.— Michael Foley (@MickFoley76) December 23, 2017
Tremendously sad. The world has lost a giant of a man in Maurice Hayes. RIP. Was so lucky to have interviewed him this year. https://t.co/2ZGbmdzgEA— Declan Bogue (@DeclanBogue) December 23, 2017
Ah, Maurice Hayes. Now that was a life. RIP— Malachy Clerkin (@MalachyClerkin) December 23, 2017
RIP Maurice Hayes, forever indebted in @OfficialDownGAA— John McAreavey (@john_mcareavey) December 23, 2017
Former South SDLP MP, Margaret Ritchie described him as "the ultimate Gael, a person of immense intellect."
Sinn Féin's South Down MP, Chris Hazzard described him as "a giant of a man" and said "his family, county and country will miss him."
The former Ulster Unionist MP and member of the House of Lords, John Taylor, said he was "very sorry to hear of the death of Dr Maurice Hayes. He was very approachable and served the people of Northern Ireland with great distinction."