Muhammad Ali was an "angel" and a "god-sent blessing to this Earth", his brother Rahman said following the boxer's death at the age of 74.

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

His family's spokesman Bob Gunnell confirmed he died on Friday evening local time.

Ali's younger brother Rahman Ali, who was also a heavyweight boxer, said he was a "sweet, kind, nice" man who "was the world's most famous person".

He told the BBC: "There was nobody on this Earth more famous than Muhammad Ali, he was known in every country.

"God blessed him because he was such a sweet person. My mother and father were sweet, good people, and he came from good stock. He was a wonderful, wonderful, wonderful man, he will be missed."

Mr Ali said his brother's spirit, both inside and out of the ring, came from the upbringing their parents gave them, but said he was "one of a kind", adding: "There will never be another Muhammad Ali.

Speaking through tears, he said he remembered Ali "hugging me, making me laugh, kissing me", and said he was so kind he would give you the shirt from his back.

He said: "He loved everybody, he had a good heart. So I cry from joy, and happiness."

Asked how he wanted Ali to be remembered, he said: "I want Muhammad to be remembered as a humanitarian, a loving, kind, sweet, good man."

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

Flags are flying at half mast in Ali's home town of Louisville, Kentucky, where the funeral will take place.

Tributes have flooded in from around the world, with friends and fellow fighters paying Ali, who was voted Sports Personality of the Century, the highest accolades.

US president Barack Obama said he "shook up the world and the world is better for it".

In a heartfelt tribute Mr Obama revealed he keeps a pair of Ali's gloves in his private study at the White House, and said we are fortunate that "the Greatest chose to grace our time".

And he described him as "a man who fought for us. He stood with King and Mandela; stood up when it was hard; spoke out when others wouldn't".

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, telling the BBC: "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."

He also spoke of Ali's love for the UK and the way he was treated in the country.

"He loved London. If he had been born and raised in London he never would have changed his name," he said.

Ali, widely considered to be the greatest in boxing history - as well as a key figure in America's civil rights movement - is survived by his fourth wife Lonnie, whom he married in 1986, and nine children, many of whom were reported to have flown to their father's bedside on Thursday and Friday.

At his last public appearances he looked increasingly frail, including on April 9 when he wore sunglasses and was hunched over at the annual Celebrity Fight Night dinner in Phoenix, which raises funds for Parkinson's treatment.

Ali had suffered from Parkinson's for three decades, the extent of his illness brought to the world stage when he trembled badly while lighting the Olympic torch in 1996 in Atlanta.

Doctors say the Parkinson's was probably caused by the thousands of punches Ali took during a career which saw him win 56 of his 61 bouts.

Ali, who changed his name from Cassius Clay to throw off what he saw as the yoke of racism, first came to prominence when he won gold at the age of 18 at the 1960 Rome Olympics in the heavyweight division.

He went on to become the first man in history to win the world heavyweight title three times, and along the way fought race wars, was stripped of his world title for refusing to fight in the US war in Vietnam and lost his boxing licence for close to four years as a result.

He was outspoken, eloquent and poetic, perhaps his most famous quip being that he would "float like a butterfly, sting like a bee".

Many in the UK will remember Ali's four appearances on Sir Michael Parkinson's chat show in the 1970s and 1980s.

Sir Michael said: "He was not a man without flaws. You have to consider those. But if you wanted to concentrate on what was attractive about him I could talk forever."

He added: "I could not believe how beautiful he was. He was an extraordinary looking man. He was graceful and all those things and, of course, he was as funny as hell."

Ali's biographer Thomas Hauser told the BBC that Ali was "beautiful inside and beautiful outside". He tweeted that Ali's death was "the passing of a legend".

Retired Irish boxer Barry McGuigan told the BBC Ali was "a remarkable human being", saying: "More than anything else it was how humble and how brilliantly charismatic he was. He was a beautiful looking man, a beautiful looking individual and he had so much compassion."

He added: "He was the greatest sportsman there has ever been and we were very lucky that he chose boxing."