Former Heavyweight Boxer Tommy 'The Duke' Morrison Dies

Tommy Morrison, a former heavyweight champion who gained fame for his role in the movie "Rocky V," has died.

He was 44.

Morrison's former manager, Tony Holden says his longtime friend died Sunday night at a Nebraska hospital. The family would not disclose the cause of death. Morrison tested positive for HIV in February 1996.

Morrison was born in Arkansas and grew up in Oklahoma.

In 1993, Morrison beat George Foreman to win the World Boxing Organization heavyweight title. His last Nevada-sanctioned fight was in 1995, a loss to Lennox Lewis.

Morrison went on to fight again in Japan nine months later, earning a TKO that kept his career on track for what would have been a massive payday: a showdown against Mike Tyson.

However, just as his boxing career and general celebrity were cresting, Morrison tested positive for HIV in 1996 before a fight with Arthur Weathers, which he said afterwards effectively put the brakes on his rise. In the years that followed, he claimed the test was a false-positive, and even invited the New York Times to test him for HIV in 2007.

That test, as well as two others for the sports sanctioning body in West Virginia, supported Morrison's assertion that he did not have the virus, the Times reported, although there was some doubt as to whether the blood provided for the tests was in fact Morrison's blood.

Morrison got in the ring two more times, once in 2007 in West Virginia and once in 2008 in Mexico, earning TKOs against lesser-known opponents.

His wife, Trisha Morrison, whom he married in 2011, said in a recent interview with ESPN.com that Morrison had Guillain-Barre Syndrome, not HIV.

Regardless, after the 1996 positive test, Morrison became a spokesman for AIDS awareness and safe sex, creating the KnockOut AIDS Foundation, although it is unclear how active the charity is today. He said in interviews in the late 1990s he suspected his promiscuous lifestyle had led him to contract the disease.

Reports say Morrison succumbed to respiratory and metabolic acidosis and multiple organ failure.