Former heavyweight boxing champion Tommy Morrison, who gained fame for his role in the movie “Rocky V,” died Saturday night in an Omaha hospital at age 44.

The family would not disclose the cause of death, but published reports list respiratory and metabolic acidosis and multiple organ failure.

Morrison was already a successful boxer when in 1989  Sylvester Stallone  saw one of his bouts, arranged a script reading, cast him Rocky V as Tommy “The Machine” Gunn, a young and talented protege of the retired Rocky Balboa.

Morrison’s boxing career hit its peak after the movie. In 1993, he beat George Foreman to win the World Boxing Organization heavyweight title. Two years later, he lost the title to former WBC champion Lennox Lewis, who knocked him out.

Morrison…who was born in Arkansas and grew up in Oklahoma…tested positive for HIV in 1996 and retired from boxing, but returned to the ring in 2007 after years of antiretrovirus medication dropped his viral load to almost undetectable levels.