Eloi Vasquez's uncle told KTVU that the 19-year-old student-athlete's body was found fatally struck by a vehicle on the freeway about a mile from the USC campus.
The family learned of his death around 11 a.m. Monday.
The news came after the Los Angeles Police Department and Vasquez's family asked for the public's help in finding him after he stepped out of a party early Saturday morning and never returned.
Vasquez, a freshman and member of UC Berkeley's men's soccer team, was last seen at a party held by the Tau Kappa Epsilon chapter at the University of Southern California early Saturday morning, Cal Athletics officials.
He was last heard from at about 2:15 a.m. Saturday, Cal officials said.
Los Angeles police said Vasquez reportedly told his friends he wanted to take a walk and that he didn't have any money or an identification card with him.
About 10 minutes later, the California Highway Patrol responded to a report of a fatal collision with a pedestrian on eastbound Highway 10. The Los Angeles County coroner's office has since confirmed that the pedestrian struck was Vasquez.