A grizzly bear who became a Hollywood star could be put down after killing his trainer with a single bite to the neck.

The grizzly, named Rocky, who stands 7ft 6in (2.28m) tall and weighs 50 stone (318kg), has been described as “the best working bear in the business”. He can be seen in the new film Semi-Pro when Will Ferrell’s character wrestles Dewey the Killer Bear to promote his basketball team.

But a training session at the California compound of Predators in Action, which provides exotic animals to Hollywood, ended tragically on Tuesday. Three handlers were working with Rocky when he lunged at Stephan Miller and bit him on the neck.

“It was just an initial single bite. There was no other further aggression,” said Maurice Moore, of the San Bernardino fire department. “He was used to people, used to these trainers. This happened to be a sad accident.”

The two uninjured handlers were able to use pepper spray to force the bear back into his chain-link pen.

The 39-year-old victim was an experienced animal trainer with credits for such films as The Jungle Book: Mowgli’s Story and The Island of Dr Moreau. He was a cousin of Predators in Action owner Randy Miller, the stuntman who wrestled Rocky as Will Ferrell’s body-double in Semi-Pro.

Randy Miller won a World Stunt Academy Award for wrestling tigers in the 2000 blockbuster Gladiator and has performed stunts with his animals in such films as The Postman and The Last Samurai.

Randy Miller praised the bear in an interview in February with the San Bernardino Sun, but added: “If one of these animals gets a hold of your throat, you’re finished.”

Predators in Action keeps four African lions, four tigers, a black leopard, a cougar and one other grizzly bear on its 55-acre property in the San Bernardino mountains east of Los Angeles.

The company’s website says Rocky and the second grizzly, named Dakota, “have worked on some of the wildest jobs ever done”.

“They are world famous for wrestling scenes they have done in films and live shows. These bears are hard working and known for long runs, great action and staged attacks. They are good around people but can look extremely dangerous.” Rocky’s fate will now be decided by local animal care officials.

Denise Richards, who works with wild animals at nearby Moonridge Zoo, said trained animals that turn on their handlers are often destroyed. “You can train them and use as many safety precautions as you can, but you’re still taking a chance if you’re putting yourself in contact with them,” she said.

“It’s still a wild animal. Even though it may appear that the bear attacked for no reason, there was a reason. I’m sure Randy understands why it happened. They’re not cold-blooded killers.”

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