Former world junior-lightweight and lightweight boxing champion Diego Corrales was killed while riding a motorcycle Monday night in Las Vegas.

Las Vegas police still were investigating what appeared to be a traffic accident. But Ray Woods, Corrales’ stepfather and former trainer who lives in Sacramento, Calif., said he received a call from Corrales’ wife, Michelle, who told him the 29-year-old fighter was riding on a recently purchased motorcycle in the Las Vegas area and apparently struck two vehicles.

“My God, I can’t believe it. It was such a shock,” Woods said in a phone interview with Corrales’ mother, Olga, nearby. “I didn’t want to believe it at first, but Michelle was crying as she began talking to us, so we knew something terrible had happened.”

Corrales, who was reared in Sacramento and lived in Las Vegas, had a domestic violence conviction involving his first wife in 2001. They had one child. Michelle, who is pregnant, and Diego Corrales have one son, 15 months old.

Corrales (40-5, 33 knockouts) won the International Boxing Federation junior-lightweight title in 1999. But his greatest achievement came in a 2005 World Boxing Council lightweight title fight in which he survived two knockdowns in the 10th round to dethrone Josi Luis Castillo on a 10th-round knockout.

In a rematch, Corrales was knocked out in the fourth round but retained the title because Castillo failed to make the mandatory predetermined weight limit of 135 pounds. Corrales forfeited the title last October when he weighed over the limit against Joel Casamayor, who won a split decision. He also lost his final fight, April 7 against Joshua Clottey, by decision.