Tributes have poured in following the death of Muhammad Ali:
:: "He's the most transforming figure of my time, certainly. He did more to change race relations and the views of people than even Martin Luther King. It was a privilege and an honour for me to know him and associate with him" - Bob Arum, who promoted 26 of Ali's fights.
:: Ali, Frazier & Foreman we were 1 guy. A part of me slipped away, "The greatest piece" - tweet by George Foreman, Ali's opponent in the Rumble in the Jungle.
:: "Muhammad Ali is a legend and one of the world's most celebrated athletes, the fighter who ushered in the golden era of boxing and put the sport on the map. He paved the way for professional fighters, including myself, elevating boxing to become a sport watched in millions of households around the world" - boxer Oscar De La Hoya, who won titles at six different weight classes.
:: "We lost a giant today. Boxing benefited from Muhammad Ali's talents but not nearly as much as mankind benefited from his humanity. Our hearts and prayers go out to the Ali family. May God bless them" - boxer Manny Pacquiao, a champion in eight weight classes.
:: "Passing the Olympic torch to Muhammad to light the cauldron at the Atlanta Games in 1996 was the defining moment of my career, and a memory I will treasure forever, as much as any of the medals I won. As Olympians, our role is to inspire others to achieve their dreams, and no person has ever lived that role more than Muhammad Ali" - swimmer Janet Evans.
:: "Without question his legacy is one that he defied the odds because he stood up for what he believed in and when he was put to the test he took personal harm rather than go against his beliefs and what he stood for" - Don King, promoter of Rumble in the Jungle and Thrilla in Manilla.
:: "We are proud to call Ali not only a member of Team USA, but an Olympic champion. With unparalleled grit and determination, he left a legacy that will continue to inspire generations of Americans for years to come" - Scott Blackmun, chief executive of the US Olympic Committee.
:: "Hillary and I are saddened by the passing of Muhammad Ali. From the day he claimed the Olympic gold medal in 1960, boxing fans across the world knew they were seeing a blend of beauty and grace, speed and strength that may never be matched again. We watched him grow from the brash self-confidence of youth and success into a manhood full of religious and political convictions that led him to make tough choices and live with the consequences. Along the way we saw him courageous in the ring, inspiring to the young, compassionate to those in need, and strong and good-humored in bearing the burden of his own health challenges. I was honoured to award him the Presidential Citizens Medal at the White House, to watch him light the Olympic flame, and to forge a friendship with a man who, through triumph and trials, became even greater than his legend. Our hearts go out to Lonnie, his children, and his entire family" - former US president Bill Clinton.
:: The head of the Nelson Mandela Foundation said the former South African president called Muhammad Ali his boxing hero.
:: "Madiba had great respect for his legacy and spoke with admiration of Ali's achievements," Sello Hatang, the foundation's chief executive said. The statement included a comment Mandela made at an event in Washington in 1990: "There is one regret I have had throughout my life: that I never became the boxing heavyweight champion of the world."