Dave Goldberg, CEO of SurveyMonkey and husband of Facebook COO Sheryl Sandberg, died of "head trauma" after "he fell off the treadmill and cracked his head open", said a spokesman for the prosecutor's office in the Mexican state of Nayarit.
The announcement of Goldberg's cause of death came four days after his death was announced on May 1, leading to speculation Mexican authorities had looked deeper into the fatal incident.
Investigation showed Goldberg bled to death. It revealed Goldberg left his room at the Four Seasons Resort near Punta Mita, close to Puerto Vallarta in southwest Mexico around 4:00 p.m. on May 1 to exercise at the resort's gym.
He was vacationing at the resort with his wife, Sheryl, when the fatal accident occurred.
Mexican authorities said Goldberg appears to have slipped off a treadmill and was knocked unconscious after he hit his head on the gym floor. Goldberg died of head trauma and blood loss, said investigators. He was found with his head in a pool of blood, his skull apparently split open.
Goldberg's brother, Robert, found him on the floor of the gym at around 7:00 p.m., said The New York Times.
What remains unclear is if Goldberg was all alone in the gym at the time the accident occurred, and why his three hour disappearance aroused no suspicions among his wife and the members of his entourage.
The Mexicans, however, have ruled Goldberg's death an accident.
Goldberg was taken to Hospital San Javier in Nuevo Vallarta where he died.
His wife has so far made no public statements about her husband's death.