The mother of Puerto Rican former boxer Hector "Macho" Camacho says he is to be taken off a life support machine, against the wishes of his eldest son.
The three-time world champion, whose opponents included Sugar Ray Leonard, is clinically brain dead after being shot in the head, doctors say.
He suffered a heart attack after a drive-by shooting on Tuesday outside the capital, San Juan.
A final decision is expected later on whether to remove life support.
It is thought the former champion's mother, Maria Matias, has the final say in the matter.
Ms Matias said doctors should remove life support from the boxer after three of his sons had been given a chance to see him for a final time on Saturday.
"I lost my son three days ago. He's alive only because of a machine," she said.
But Camacho's eldest son, Hector Jr, was quoted as saying he wanted to keep his father alive.
"He's going to fight until the end. My father is a boxer," he said.
Camacho, 50, was sitting in a car outside a bar on Tuesday with a friend when it was fired on.
His friend, Adrian Mojica Moreno, was killed in the attack. Police say they do not know of any motives for the shooting.
Camacho fought some of the great names of boxing - Oscar de la Hoya, Sugar Ray Leonard and Felix Trinidad.
But in recent years he was convicted of burglary, found in possession of drugs and the subject of domestic abuse complaints from his former wife.
He continued to box, losing a fight to Saul Duran in May 2010, and had been discussing another bout scheduled for next year.