THE sporting world are mourning the loss of ‘The Greatest’ after boxing legend Muhammad Ali died at 74 on Friday night.

The three-time world heavyweight champion, who had battled Parkinson's disease for 32 years, was admitted to hospital with a respiratory condition earlier in the week.

His family's spokesman Bob Gunnell confirmed Ali's death in Phoenix, Arizona, on Friday evening local time.

A statement from the spokesman said that the Ali family "would like to thank everyone for their thoughts, prayers and support" and asked for privacy.

Tributes have been pouring in for Ali, born Cassius Clay, since the news of his death broke.

George Foreman, Ali's friend and rival from the famous 'Rumble in the Jungle' fight, said: "We were like one guy - part of me is gone."

He said he wanted Ali to be remembered as a "brave" humanitarian and not just a boxer.

He said: "Muhammad Ali was one of the greatest human beings I have ever met. No doubt he was one of the best people to have lived in this day and age.

"To put him as a boxer is an injustice."

Another former heavyweight boxing champion, Evander Holyfield, told MSNBC: "I'm glad to have known Ali because when I was a kid, at eight-years-old, I was told I would be like Ali.

"To take it upon yourself and say, 'I'm the greatest', you put yourself in a position for people to take pot shots at you. This is what Ali did. It's amazing him becoming three-time heavyweight champion of the world. At that time people thought 'who could beat three?'.

"You have to be stronger to get up from a loss to go on, and that's what Ali proved to be."

Ali became a household name by winning gold at the 1960 Rome Olympics in the heavyweight division.

He soon turned professional and, fighting under his original name of Clay, he made his debut in October 1960 with a sixth-round decision over Tunney Hunsaker in his home city of Louisville.

After 15 straight wins, he pulled off a notable stoppage of fading former light-heavyweight champion Archie Moore in November 1962.

In 1964, after rising off the floor to beat Henry Cooper in London, Clay stunned the seemingly invincible Sonny Liston with a seventh-round win at Miami Beach to win the world heavyweight title.

It was the beginning of a 16-year odyssey, which would see him become the first man in history to win the world heavyweight title three times and would take his remarkable road-show to all corners of an enraptured globe.

Popularity, however, was slow in coming. The public did not take so kindly to the new champion's brash and boastful antics, not least when he announced he had joined the Black Muslim movement of Malcolm X and changed his name to Muhammad Ali.

Fights outside the ring continued apace too.

He fought race wars, was stripped of his world title for refusing to fight in the US war in Vietnam and lost his boxing license for close to four years as a result.

The first loss of his professional career – to Joe Frazier – was dubbed 'The Fight of the Century', although he got his title back with a victory over George Foreman in the 'Rumble in the Jungle' in 1974.

Other all-time great fights followed, such as the 'Thrilla in Manila' when he stopped Frazier after 14 arduous rounds.

In the end, he called time in 1981 with a record of 56 wins from 61 fights and with a worldwide following of fans.

The funeral will take place in Ali's home town of Louisville, Kentucky.