The newspaper Daily Telegraph, from Sydney, noted that Ritchie was hit in the body in a 'sparring' session with Jeff Horn, a former welterweight champion.
According to the newspaper, Ritchie reached back to his corner of the ring and collapsed. Despite efforts to help him, the boxer did not survive.
Ritchie's promoter, Jake Ellis, confirmed the news on the Facebook network. "It is with enormous sadness that I must announce that Dwight Ritchie died doing what he loved most"As a promoter and friend of Dwight it is unbearable to accept this tragic news," he added.
Ritchie, who used the nickname "Cowboy Fighter", exhibited a record of 19 wins and two losses as a professional.
In his last fight, held in August, he had unanimously lost to Australian Tim Timzyu, for the IBF Australasia crown in the super welterweight category.
On the social network Instagram, Tszyu said he felt "truly sad with the death of Dwight Ritchie. Only fighters understand the bond that unites them, especially those with whom the ring is shared. Rest in peace, champion."
Ritchie's death occurred less than a month after the American Patrick Day lost his life as a result of a brain injury after his knockout loss to Charles Conwell, in Chicago.
Argentina's Hugo Santillan died in July this year after a fight in the city of San Nicolas, north of Buenos Aires, just two days after the Russian Maxim Dadashev died due to injuries sustained in a fight in Maryland, United States .