Star Trek actor Walter Koenig, who played Pavel Chekov, dies aged 90

Walter Koenig, who played the spirited Russian crewman Pavel Chekov in the original Star Trek TV series, has died aged 90.

The US actor was a mainstay on the show from season two in 1967 until it ended in 1969, later reprising his role as the eager and earnest Chekov in the six original cast movies from 1979 through to 1991.

In the mid-late 1990s, Koenig portrayed a very different character, the ruthless Psi Corps telepath Alfred Bester, in another sci-fi space series, Babylon 5.

His Star Trek co-star George Takei, who played Hikaru Sulu, led the tributes on social media on Monday, writing: "Walter was more than Chekov. He was a writer, a teacher, a thoughtful man, and a loyal friend."

Representatives for Koenig said in a statement given to the BBC: "Today we mourn the passing of Walter Koenig, whose talent, warmth, and unforgettable performances left a lasting mark on generations of fans around the world."

They confirmed he had died "of old age at home in North Hollywood" on Sunday night, "surrounded by his daughter and niece".

Koenig's Chekov - with his Monkees-style mop-top haircut - added heart and humour to the Starship Enterprise crew's adventures

He also wrote an episode for the show's animated spin-off.

Born in Chicago and raised in Manhattan, Koenig was the son of Soviet Jewish immigrants whose family had lived in Lithuania.

He studied at the famous Neighborhood Playhouse School of the Theatre in New York, alongside the likes of James Caan, Christopher Lloyd and Dabney Coleman.

His big break came as the capable young Chekov, who would often joke that everything was invented in Russia.

The character, who served as the navigator on the USS Enterprise, was introduced to appeal to younger audiences.

But Star Trek creator Gene Roddenberry's studio also publicised the role as a response to criticism in Pravda, the main newspaper of the Soviet Communist Party, about the lack of a Russian character. This was a claim Koenig later denied.

The show, which aired during the Cold War and Space Race between the US and Soviet Union, imagined a future in which nations worked together, and Chekov's Russian heritage fitted that ideal.

Koenig once said that the character's purpose on the NBC show was to "set out the bones of the plot and let McCoy, Spock and [William Shatner's Captain] Kirk fill it in", according to the Hollywood Reporter., external

He was arguably more integral to the plot of the movies, being nominated by the Academy of Science Fiction, Fantasy & Horror for his work on The Wrath of Khan (1982) and The Voyage Home (1986).

His seventh Star Trek film appearance was a brief one in Generations (1994) - mainly a next generation film - and he later voiced President Anton Chekov in Star Trek: Picard in 2023.