Image copyright Getty Images Image caption Dave Legeno (right) competed as a mixed martial arts fighter

A British actor who appeared in the Harry Potter film series has been found dead in a remote part of California's Death Valley, authorities say.

Mixed martial arts fighter Dave Legeno, 50, was found by hikers on Sunday and his body was recovered by helicopter.

There were no signs of foul play and it is believed he died from the heat, an initial coroner's examination found.

He appeared as werewolf Fenrir Greyback in three Harry Potter movies, including both Deathly Hallows films.

'Kind gentleman'

"It appears that Legeno died of heat-related issues, but the Inyo County coroner will determine the final cause of death," the Inyo County Sheriff's Office wrote in a statement.

Actor Tom Felton, who played Draco Malfoy in the films, paid tribute on Instagram, saying: "He was a great talent with a heart of gold and always had time for anyone.

"Dave was a soft, kind gentleman off screen but had the skill to be the complete opposite on screen. He taught me lots."

Legeno also appeared on TV and in films including Snow White and the Huntsman and Batman Begins.

The tall, muscular one-time professional boxer was set to star in an upcoming film titled Sword of Vengeance prior to his death.

He is survived by a daughter, US media report.