"We have lost one of ICTR's key contributors in shaping an international justice system," Roland Amoussouga, spokesman of the UN Court told Hirondelle News Agency.
Judge Williams resigned in March 2004 "for personal reasons" after serving the tribunal for almost seven years.
Judge Williams was elected to the ICTR by the United Nations General Assembly in November 1998, and was re-elected in January 2003.
Judge Williams was born in June 1927 and began his career as Barrister-at-Law in 1959 in England.
He later practiced in Jamaica before becoming Director of Public Prosecutions in Antigua from 1978 to 1982 and Solicitor General in 1982.
From 1983 to 1992 he was High Court Judge of the Eastern Caribbean Supreme Court. He was appointed Queen's Counsel in 1981 by Her Majesty Queen Elizabeth II for distinguished service in the field of law.
He is the third judge to have passed away since the creation of the ICTR by the UN Security Council in 1994 to try the key perpetrators of the Rwandan genocide.
The first President of ICTR, Judge Laity Kama (Senegal) passed away in May 2001 at the age of 62 in a Nairobi Hospital after a short illness to be followed by Judge Asoka de Zoysa Gunawardana (Sri Lanka) who retired in June 2004 because of ill health and shortly thereafter died.
© Hirondelle News Agency