Sports stars and celebrities pay tribute to Muhammad Ali

Sports stars and celebrities, including Justin Bieber, Mike Tyson, and Madonna, have paid tribute to Muhammad Ali following his death on Friday (03Jun16).

The 74-year-old boxing hero was admitted to a medical centre in Phoenix, Arizona, for respiratory complications earlier this week (beg30May16), and reports suggest he spent his final few hours on life support.

Family spokesman Bob Gunnell confirmed the sad news of Ali's passing in a statement released late on Friday.

"After a 32-year battle with Parkinson's disease, Muhammad Ali has passed away at the age of 74," he wrote. "The Ali family would like to thank everyone for their thoughts, prayers, and support and asks for privacy at this time."

Sports stars, actors and musicians flocked to social media to express their condolences after news of his death broke, with many posting photos paying tribute to one of the greatest sportsmen of all time.

Former boxing champion-turned-actor Mike Tyson shared a snap of the pair on Twitter, and captioned it, "God came for his champion. So long great one. @MuhammadAli #TheGreatest #RIP".

Madonna, who only recently grieved the loss of her close friend Prince, shared a photo of herself with Ali on Instagram, with the caption, "What is going on??!! We are losing all of our National Treasures. Our Pillars of Humanity. He was the Greatest!"

"This is the ALI we should all remember!" boxing fan Justin Bieber insisted beside a snap of Ali joking about in front of the camera. "The fun loving man who was fully himself!! RIP CHAMP!!!"

Rap mogul Sean 'Diddy' Combs, who has a tattoo of Ali's signature on his chest, took to Instagram to remember a meeting with his mentor and friend.

"This pic means so much to me!," he wrote. "The love he showed me he didn't have too (sic). He always was excited to see me. He even came to see me on Broadway in A Raisin In The Sun. He sat thru (sic) a 3 hr (sic) play to see me. It bugged me out. It humbled me. Thank you for the love. I MISS YOU. #RIPALI".

The rapper-turned-actor later shared a photo of his son Justin being hugged and kissed by Ali, writing, "Thank you for always showing me and my family love. He was so kind to everyone he met! I want my son @princejdc to always cherish this moment."

Star Wars actor John Boyega also marked Ali's loss on Twitter, commenting, "May our lives be an inspiration to the people around us as much as our words. The greatest. Rest easy champ", while Frozen star Josh Gad tweeted, "In a year where many greats have passed, the greatest of all has just left us. Goodbye champ. Fly like a butterfly."

Hip-hop veteran Chuck D, who narrated the Ali Rap documentary in 2006, was onstage at the Hollywood Palladium with his new rap/rock supergroup Prophets of Rage on Friday when the news of Ali's death hit headlines, and he called on fans to salute Ali by holding up their fists.

"We raise a fist and pray for Muhammad Ali," he told the crowd, who willing obliged.

Online tributes have also poured in from the likes of Jennifer Hudson, Russell Simmons, Kelly Rowland, Ciara, Lenny Kravitz, and Kate Hudson, among many others.