Muhammad Ali will be laid to rest in his Kentucky home town of Louisville followed by a memorial service led by Bill Clinton, it has been announced, after it was revealed the three-time world heavyweight champion died of septic shock.

Flags have been flying at half-mast on all public buildings in Louisville, where former US president Clinton will lead eulogies at a public memorial on Friday, as well as actor Billy Crystal and American TV sports presenter Bryant Gumbel.

A procession on Friday will take Ali’s body through the streets of Louisville, past the Muhammad Ali Center, travel along the street named after him – the Muhammad Ali Boulevard – and through the neighbourhood where he grew up, “to allow anyone who’s there from the world to say goodbye”, his spokesman, Bob Gunnell, said.

He will be buried at Cave Hill cemetery in a private family ceremony, and an interfaith memorial service, broadcast online, will follow at the town’s sports arena.

Rahman Ali paid tribute to his “sweet, kind” brother.

“There was nobody on this Earth more famous than Muhammad Ali, he was known in every country,” he said. “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. There will never be another Muhammad Ali.”

Ali said his brother, who suffered with Parkinson’s disease for more than 30 years, had “loved everybody, he had a good heart. So I cry from joy, and happiness. I want Muhammad to be remembered as a humanitarian, a loving, kind, sweet, good man.”

The boxer, who had nine children, died with his family around his hospital bed. Hana Ali said his heart did not stop beating for 30 minutes after all other internal organs had failed.

On Saturday, Barack Obama led tributes in a deeply personal statement, which revealed he kept a pair of Ali's boxing gloves in his private study.

It said: “Muhammad Ali was the Greatest. Period. If you just asked him, he’d tell you. He’d tell you he was the double greatest; that he’d ‘handcuffed lightning, thrown thunder into jail’. But what made the champ the greatest . . is that everyone else would tell you pretty much the same thing. Muhammad Ali shook up the world. And the world is better for it. . .”

Ali's death leaves George Foreman as the sole survivor of the golden age of the heavyweights.

"Each time one of us leaves, I tell everybody: Muhammad Ali, Joe Frazier, George Foreman, we were really just one guy," said Foreman. "And every time one slips away, you feel like you've lost a piece, and Muhammad Ali was the greatest piece of all." Guardian Service