* Shot in face while sitting in a car with a friend
* Police say cocaine found in vehicle, no arrests made
* Battled drug and alcohol problems throughout career (Adds boxing career highlights)
SAN JUAN, Puerto Rico, Nov 24 (Reuters) - Three-time world boxing champion Hector "Macho" Camacho died on Saturday, four days after he was shot in the face in a drive-by shooting, doctors said. He was 50.
Camacho was pronounced dead after being taken off life support following a second heart attack early Saturday morning, Rio Piedras Medical Director Ernesto Torres told reporters.
Puerto Rico officials planned a public wake for the boxer at the Department of Sports & Recreation headquarters in San Juan, but details were pending.
The former U.S. boxing champ had been declared brain dead on Thursday after he was shot on Tuesday while sitting in a car with a friend, Adrian Mojica Moreno, 49, outside a liquor store in the San Juan suburb of Bayamon, Camacho's birthplace.
Two gunmen opened fire on the car, killing the driver, Mojica Moreno, and hitting Camacho in the jaw. The bullet fractured two vertebrae and lodged in his shoulder, damaging the arteries that carried blood to the brain, doctors said.
Police said they found nine small bags of cocaine in the driver's pockets and one open in the car. The shooting is under investigation and no arrests have been made.
Camacho, a left-handed fighter who grew up in New York's Spanish Harlem neighborhood, had a record of 79-6-3 with 38 knockouts. His three-decade career featured fights with a "who's who" of boxing and a flamboyant style that included entering the ring in an outfit based on the Puerto Rican flag.
Camacho won titles in three weight classes - super featherweight, lightweight and junior welterweight - during a storied professional career. He won his first world championship in 1985 and his last in 1991. His final match came in 2010.
The fast, quirky fighter beat some of the toughest boxers of his day, including Roberto Duran and Sugar Ray Leonard, who retired after Camacho knocked him out. Others included Julio Cesar Chavez, Felix Trinidad and Oscar De La Hoya.
But Camacho also fought against drug and alcohol problems during his career. He was sentenced to seven years in prison in 2007 for the burglary of a Mississippi computer store. During the arrest, he was found to be in possession of the drug Ecstasy.
All but one year of the sentence was suspended and he was given probation. He violated probation, however, and served two weeks in jail.
Camacho's body was taken to the hospital's pathology section and brought to the Institute of Forensic Sciences as required by law, Torres told reporters.
The family planned a funeral in New York, El Nuevo Dia newspaper reported.
Family members had debated removing him from life support, with some including his son Hector "Machito" Camacho holding out hope for his recovery.
On Friday evening, his mother, Maria Matias, told reporters at the medical center that "God has taken him" and that she was waiting for Camacho's other children to arrive in Puerto Rico before having him disconnected.
Camacho Jr. lamented the crime and violence in Puerto Rico. "You have to stop the violence and the drugs. Rap singers have to stop glorifying violence. This is for the youth. All the street promises them now is death, drugs and jail." (Reporting by Reuters in San Juan; Editing by Barbara Goldberg, Sandra Maler and Xavier Briand)