BROCK PETERS was best known for his moving and dignified portrayal of Tom Robinson, the black man wrongly accused of raping a white girl in the classic American drama To Kill a Mockingbird (1962). He appeared in dozens of other movies in a career spanning half a century and is fondly regarded by Star Trek fans for his contribution to the series on both film and television.

A towering figure, with a rich, booming voice, he provided backing vocals for Harry Belafonte’s Banana Boat Song (Day-O) and played the Star Wars villain Darth Vader on radio. But he could display dignity as readily as menace: when asked by the defence lawyer Atticus Finch (Gregory Peck) if he raped the girl in To Kill a Mockingbird he delivered the line “I did not, sir”, with tears in his eyes. There was enough integrity and suppressed anger to convince of his innocence and elicit sympathy at his plight and the injustices prevalent in Alabama in the 1930s, when the story was set. For such a commanding figure, he displayed great sensitivity and gentleness in his characterisations.

Born George Fisher, of African and West Indian stock, in New York, he grew up in poverty in Harlem. He decided early that he would like to act and attended the famed Music and Arts High School. He studied at Chicago University and New York City College, did odd jobs, including as a hospital orderly and shipping clerk, and made early stage appearances in Porgy and Bess and South Pacific.

In the late 1940s he toured as bass soloist with the De Paur Infantry Chorus and sang in cabaret. He made his film debut as a belligerent sergeant in Carmen Jones (1954), an African-American spin on Bizet’s opera set in an army camp and starring Harry Belafonte and Dorothy Dandridge. In 1959 he was reunited with Dandridge in the film of Gershwin’s musical Porgy and Bess, playing Crown, while Sidney Poitier played Porgy. Both films were directed by Otto Preminger.

Peters’s bulk, very dark skin, piercing white eyes and terrifying scowl were in keeping with a stereotypical white American vision of black villainy, but it was as the sympathetic Tom Robinson in To Kill a Mockingbird that Peters made his most indelible impact on audiences. The film was based on the Harper Lee novel that skilfully juxtaposed childhood innocence and the cancer of racism. It marked the beginning of a long friendship with Peck, who won an Oscar for his performance; Peters read the eulogy at Peck’s funeral two years ago.

The book and the film have become landmarks in popular American culture and important social documents, studied at schools in the US and UK. Ironically perhaps, it was in England that Peters broke free of any lingering danger of typecasting, first as a homosexual jazz musician who shares lodgings with Tom Bell and a pregnant Leslie Caron in Bryan Forbes’s touching drama The L-Shaped Room (1962), and then as the dustman who is appointed church warden to Peter Sellers ’s working-class vicar in the Boulting Brothers’ ecclesiastical comedy of class and mistaken identity Heavens Above! (1963).

Back in the US he played a racketeer in Sidney Lumet’s drama The Pawnbroker (1964), with Rod Steiger, and was part of Charlton Heston’s motley band on the trail of Apaches in Sam Peckinpah’s Major Dundee (1965). Peters and Heston first worked together — almost — on the stage, in an intriguing Broadway production of Romeo and Juliet in which the Capulets were all to be black and the Montagues white, with the two actors duelling as Tybalt and Mercutio. It predated West Side Story by years, but financing fell through after the play was fully rehearsed. Peters and Heston worked together again on the chilling futuristic tale Soylent Green (1973) and on the thriller Two-Minute Warning (1976).

Peters tapped into the Star Trek phenomenon as Admiral Cartwright in Star Trek IV: The Voyage Home (1986) and Star Trek VI: The Undiscovered Country (1991) and he was also in several episodes of Star Trek: Deep Space Nine in the 1990s as Commander Sisko’s father. Other films and television include the western The McMasters (1970), the “blaxploitation” thriller Slaughter’s Big Rip-Off (1973), Roots: The Next Generations (1979), Ghosts of Mississippi (1996) and The Wild Thornberrys Movie (2002), for which he provided the voice of Jomo.

He had a lifetime achievement award from the Screen Actors’ Guild and a star on the Hollywood Walk of Fame and is in the Black Filmmakers Hall of Fame. Peters is widely regarded as a role model for a generation of black American actors, not just because of his work in films and the theatre work, but also for his commitment to the progress and rights of African-American actors and his involvement in humanitarian causes and community politics.

Throughout his career Peters also appeared regularly on stage. He was an obvious choice for Othello, won several awards and a Tony nomination for his performance as a South African minister in Lost in the Stars (1972), the Broadway musical version of Cry, the Beloved Country (he reprised the role in 1974 in a film version), and he starred in a Los Angeles production of Driving Miss Daisy (1989), with Julie Harris.

Peters married in 1961 the television producer and fellow activist DiDi Daniels, with whom he formed a production company. The marriage lasted till her death in 1989.

He is survived by their daughter, and by his partner, Marilyn Darby.

Brock Peters, actor, was born on July 2, 1927. He died on August 23, 2005, aged 78.