Born in Gravette, Ark., Morrison began boxing at age 10 and fought in his first professional match in 1988.
Nicknamed "The Duke," Morrison was diagnosed as being HIV-positive in 1996 and banned from the sport for 10 years; however, he and his wife Trisha denied up until his death that he had the virus that causes AIDS. He died Sunday at a hospital in Nebraska, and the cause of death was not disclosed, his friend and promoter Tony Holden told the AP.
"That's the way Tommy took off after he was told he was HIV-positive," Holden told the AP. "He started research on the Internet and started saying it was a conspiracy. He went in that direction and never looked back."
In 1993, Morrison beat George Foreman to earn the title of heavyweight champion. But troubles in his personal life often overshadowed his professional accomplishments. Throughout the 1990s and early 2000s, Morrison was charged with assault, weapons violations and multiple DUIs. He was sentenced to two years in prison in 2000, a sentence that was lengthened after he violated his parole.
Morrison attempted a comeback in 2006, saying that his HIV-positive result was a false positive.
At the end of his career, his record was 48-3-1 with 42 knockouts.