This was announced by the President of the World Boxing Council (WBC) Mauricio Suleiman, whose words are quoted by Boxing Scene.
It is noted that the cause of death of the Puerto Rican was a heart attack.
Carlos de Leon is the only boxer in history to win four times the world heavyweight title. He owned the WBC belt in 1980-1982, 1983-1985, 1986-1988 and 1989-1990.
In total, he has 53 wins, 33 of which by knockout, 8 losses and one draw.
Earlier, boxer Denis Lebedev confirmed that he had completed his sports career.