Australia's boxing community was in shock Sunday after middleweight Dwight Ritchie collapsed and died aged just 27, reportedly while sparring.
Sydney's Daily Telegraph said he took a body shot on Saturday, walked back to his corner and collapsed. He could not be revived.
It said he was sparring in Melbourne with Michael Zerefa, who is preparing for a rematch with Jeff Horn, a former WBO welterweight champion.
Ritchie's promoter Jake Ellis confirmed the news on Facebook.
"It is with great sadness and shock to announce that the fighting cowboy Dwight Ritchie sadly passed away today doing what he loved," he said.
"As Dwight's promoter and friend it's unbearable to accept the tragic news that's just surfaced." Richie, nicknamed "The Fighting Cowboy", held a 19-2 record.
He last fought in August, losing to Tim Tszyu by a unanimous decision for the IBF Australasian super welterweight title.
"I am truly saddened by the passing of Dwight Richie," Tszyu said on Instagram.
"Only fighters understand the bond shared between them, especially those who shared a ring together. Rest In Peace to a true champion."
Ritchie's death comes less than a month after American boxer Patrick Day died after suffering a serious brain injury during his knockout defeat to Charles Conwell in Chicago.
He was the third boxer to die from injuries sustained in the ring this year.
Argentina's Hugo Santillan died in July following a bout in San Nicolas, just north of Buenos Aires. His death came just two days after Russian fighter Maxim Dadashev died from brain injuries sustained in a fight in Maryland.