Howard Bingham, the long-time personal photographer and and perhaps the closest friend of boxing great Muhammad Ali, has died aged 77.
His agent Harlan Werner said Bingham died on Thursday, just over five months after three-time world heavyweight champion Ali's death.
No cause of death was given but a friend, sports writer Mohammed Mubarak, said Bingham had been in failing health in recent months following two operations.
During a friendship that spanned more than half a century, Bingham took hundreds and thousands of photographs of the boxing legend.
He captured historical sporting moments from Ali's preparation for his first championship fight against Sonny Liston in 1964 to the moment the boxer, shaking as a symptom of Parkinson's Disease, lit the Olympic torch in 1996.
Bingham also photographed Ali greeting everyone from former US president Bill Clinton to South African president Nelson Mandela and black activist Malcolm X.
Although known largely as Ali's photographer, Bingham also had a distinguished career as a freelancer, capturing the 1967 race riots in Detroit, violence at Chicago's Democratic National Convention in 1968 and feature photographs of the Black Panther Party.
"He was one of the greatest storytellers of our time," said Mr Werner. "You look at the history in his photos. And the photos themselves, they're just amazing."
Mr Werner said that the public has never seen some of the best portraits of Ali as Bingham never wanted people to think he was cashing in on their friendship.
However, he did publish a book including some of them in the acclaimed 1993 photo memoir, Muhammad Ali: A Thirty-Year Journey.
Bingham's friendship with Ali began in 1962 when as a fledgling photographer for African-American Los Angeles Sentinel newspaper he was assigned to cover a fight by an up-and-coming young boxer then known as Cassius Clay.
After the fight, Bingham invited Ali and his brother to his mother's house for dinner which sparked the beginning of an enduring friendship.
Born in 1939, Bingham failed photography class but was finally hired by the Sentinel after repeated inquiries.
"I went off on jobs, came back with underexposed film, blurred film, no film - and I always had an excuse for what went wrong," he told the Times.
Eventually he learned enough about photography on the job to land the Ali assignment.
Bingham is survived by his wife Carolyn and son Dustin. Another son, Damon, preceded him in death.