Tommy Morrison, the power-punching heavyweight with the charismatic smile and movie-star good looks, died late Sunday in an Omaha, Neb., hospital. He was 44.

No official cause of death was released, but Morrison's wife, Trisha, told MMADirt.com that he died of respiratory and metabolic acidosis and multiple organ failure. She said Morrison had Miller Fisher Syndrome/Guillain Barre Syndrome.

But Morrison was discovered to be HIV positive prior to a scheduled February 1996 bout with Arthur Weathers in Las Vegas, when he was 27. His mother, Diana, told ESPN.com's Elizabeth Merrill last month that her son was dying of AIDS.

Morrison's long-time promoter, Tony Holden, confirmed the death to the Tulsa World, but declined to speculate on cause.

Morrison, who played Tommy Gunn in the movie, "Rocky V," was 48-3-1 with 42 knockouts. He won the WBO heavyweight title in 1993 when he defeated the legendary George Foreman.

Morrison, who had one of boxing's best left hooks, had other notable wins over Razor Ruddock, Carl "The Truth" Williams, Pinklon Thomas and James "Quick" Tillis. He lost to Lennox Lewis, Ray Mercer and Michael Bentt.

After he learned of Nevada's HIV diagnosis, Morrison had his own doctor perform a test that showed that he was HIV positive. He held a news conference in Jay, Okla., that was televised live on ESPN and blamed it on a promiscuous lifestyle.

I lived a permissive, fast and reckless lifestyle. I hope I can serve as a warning that living this lifestyle can really lead to only one thing and that's misery. . . . I've never been so stupid in my life. I thought I was bulletproof and I'm not. If getting up here and confronting this problem out in the open can get just one person out there to take a more responsible attitude toward sex, then I would feel I scored my biggest knockout ever. I thought the real danger of contracting this rested in the arms of those who subjected themselves to a certain kind of lifestyle--addicts who share needles and people who practice a homosexual lifestyle. I honestly believed I had a better chance of winning the lottery than of contracting this disease. I've never been so wrong in my life. The only sure prevention of this disease is abstinence. This disease does not discriminate, and that is very, very clear to me now. It doesn't matter if you live in a drug-infested ghetto in New York City or if you live on a ranch in Jay, Oklahoma. This is something that can jump up and bite you no matter where you are at. And it doesn't matter what color you are.

But later in his life, Morrison disputed the contention that he had HIV or that he later contracted AIDS, and he actually boxed twice, once each in 2006 and in 2007.

Last month, Merrill wrote a compelling story about Morrison in which she noted his mother, Diana, believed his death was near.

According to that Aug. 23 ESPN story, Morrison was being kept alive with a feeding tube and a ventilator.

She says he has full-blown AIDS. She believes he's in his final days. His skin is jaundiced; his liver is failing. "He's too far gone," she says, flashing an incredulous look when asked whether he could recover. "He's in the end stages. That's it." She says Morrison has been bedridden for a year, can't speak and is being kept alive with the help of a feeding tube and a ventilator.

According to MMADirt, Morrison's death came at 11:50 p.m. CT on Sunday.

Services are pending.