Anton Yelchin, who played Chekov in recently released Star Trek films, has died in a car accident at the age of 27.
The actor had risen to prominence with several blockbuster films in recent years - and has a starring role in Star Trek Beyond, which is due to be released in July.
Publicist Jennifer Allen confirmed Yelchin was killed early on Sunday morning.
According to TMZ, the star died in a "freak accident" after getting pinned between his car and a brick mailbox at his home.
Yelchin was discovered after concerned friends visited his home in San Fernando Valley, California, because he had failed to attend a rehearsal hours earlier.
An only child, Yelchin was born in Russia and moved to the US as a baby with his parents, who were professional figure skaters.
Fellow TV and film stars, as well as fans, have begun paying tribute to Yelchin on Twitter.
Devastated to hear about the brilliant Anton Yelchin. He was thoughtful, kind, and gifted. My thoughts and prayers are with his family.
— Chris Evans (@ChrisEvans) June 19, 2016
This is unreal. Anton Yelchin is such a talent. Such a huge loss.
— Anna Kendrick (@AnnaKendrick47) June 19, 2016
Anton Yelchin was one of my best friends. Can't say anything that conveys what this feels like
— Kat Dennings (@OfficialKat) June 19, 2016
The sweetest, most humble, delightful, talented guy you'd ever meet. Worked together for about a year. Shocked. https://t.co/uyg2NlmhqP
— Guillermo del Toro (@RealGDT) June 19, 2016
— Bad Robot (@bad_robot) June 19, 2016