The death has been an announced of Jim McCourt, who won a bronze medal in boxing for Ireland at the 1964 Olympic Games in Tokyo.
The Belfast native was 79 and was Ireland's only medallist at the Games in the Japanese capital.
He lost a very tight semi-final bout in the lightweight divison to the Russian Velikton Barannikov, on a 3-2 scoreline.
His daughter Cathy told BBC Sport Northern Ireland that her father had died unexpectedly having recently battled illness.
Cathy McCourt revealed Barannikov had sent her father a letter years later apologising for the verdict and confirming his belief that the wrong man won the fight.
"The Russian fighter sent him a letter about 20 years ago saying that he knew daddy had won the fight," she said.
"He said daddy was the greatest fighter he had ever fought and there were many who said that he was Ireland's greatest ever amateur."
McCourt also took home a bronze medal at the 1965 European Amateur Championships in Berlin in the same grade. A year later he won gold, this time in the light welterweight division, representing Northern Ireland at the Commonwealth Games in Kingston.
In 2011, Jim McCourt was inducted into the Irish Amateur Boxing Hall of Fame.
Additional reporting PA
