Former boxer Hector "Macho" Camacho is listed in critical condition at a San Juan hospital after being shot by unidentified individuals outside a business in the city of Bayamon, Puerto Rican hospital officials said Wednesday.

The 50-year-old former boxer's condition has not improved since he was shot on Tuesday night, Centro Medico director Ernesto Torres told reporters.

"There has been no improvement. This is the toughest fight of Macho Camacho's life," Torres said, adding that the former boxer went into cardiac arrest early Wednesday but doctors managed to revive him.

Camacho was shot in the face and the bullet hit two vertebrae before lodging in his right shoulder, damaging the carotid artery, Torres said.

Adrian Mojica Moreno, 49, who was with Camacho, was pronounced dead at the scene.

Camacho is being treated with medications to help improve his condition, but he has not responded, Torres said.

"There is no type of response to pain or the medications. Macho's condition is very delicate. The prognosis is very poor," Torres said.

Macho Camacho won world junior lightweight, lightweight and junior welterweight crowns in the 1980s. His last title fight was a 1997 loss by unanimous decision to then-welterweight champion Oscar De La Hoya.

The Puerto Rican, who has battled problems with drugs and alcohol, retired from the ring in 2009 with a lifetime record of 79-5-3.

Camacho spent two months behind bars in Mississippi for a 2005 burglary and his wife filed several domestic abuse complaints against him before ultimately divorcing him. EFE