Berbick's body was discovered about 6:30 a.m. local time in Portland parish, constable Beverly Howell said. No further details were available.
After beating Ali in 1981, Berbick went on to win the WBC heavyweight title fours years later in a decision over Pinklon Thomas. His reign was short, however, as a 20-year-old Tyson knocked Berbick out in the second round of their bout on Nov. 22, 1986, to become the youngest heavyweight champion in history.
In his loss to Tyson in Las Vegas, Berbick was knocked down twice in the second round. After trying to get up from the second knockdown he fell another two times.
Berbick fought from 1976 to 2000, finishing with a 50-11 record with one draw, including 33 knockouts. He also fought for Jamaica at the 1976 Olympics in Montreal. He was a strong puncher who moved well and had the potential to be a lasting force in the heavyweight division before the emergence of Tyson.
Berbick's career soured following the loss to Tyson and he began to run into legal trouble.
In 1991, Berbick was convicted of misdemeanor assault for attacking his former business manager, who testified the boxer put a gun to her head and accused her of stealing money from him.
The following year, he was convicted of raping a family baby sitter and was sentenced to four years in prison. He also was convicted in 1992 of second-degree grand theft for forging his ex-wife's signature to get a mortgage on a home.
After serving 15 months in prison, Berbick was deported. He went to Canada, where he lived for a time following the 1976 Olympics. He eventually moved back to the U.S., but was deported a second time.
He had been living in Portland parish since 2002.
Though Berbick was believed to be 52, according to boxing records, other reports said he was as old as 56 or as young as 49.
"Legally, I'm a spirit," he once said. "I have no age."