My friend David Naden, who has died aged 91, was a Bafta award-winning film editor who made his breakthrough by editing John Irvin’s 1963 documentary about the Durham miners, Gala Day.

It was made with a £750 grant from the British Film Institute, and David cut the film with the help of fellow graduates from the London School of Film Technique (now London Film School), Jane Wood and Dai Vaughan. After Gala Day was transmitted by the BBC in 1964, the trio of editors established David Naden Associates, and the DNA collective became the base for some of the best British documentaries.

Born in Chapel-en-le-Frith, Derbyshire, David was the only child of Mabel (nee West), who worked as a village postmistress after separating from his father, Gerald Naden, a factory worker and trade unionist.

David boarded at the King’s school, Chester. On leaving he did his national service in the signal corps, then won a place to study metallurgy at Sheffield University. He left after two years, in 1956, to study then lecture at the newly established London School of Film Technique in Brixton, south London.

In 1960, he married Jennifer Smith, a children’s TV presenter. They had three children, Jon, Mo and Jess, and lived in Crystal Palace, south-east London.

Between 1965 and 1981, David cut a wide range of films, including an episode of Michael Darlow’s TV series Cities at War, The Hero City: Leningrad (1968); four dramas for the director Michael Apted, including the 1972 TV play Another Sunday and Sweet FA; and the feature film The Shadow Line (1976) by the Polish director Andrzej Wajda.

In 1978, David won a Bafta for his editing of Bamber Gascoigne’s Granada documentary series The Christians. David also edited three of Michael Grigsby’s extraordinary documentaries commissioned by Granada: Deep South (1968), about the impact of the US’s new civil rights laws, If the Village Dies (1969), commissioned to coincide with the 100th anniversary of Mahatma Gandhi’s birth, and I Was a Soldier (1970), a portrait of three young Vietnam veterans.

An avowed socialist and humanist, David worked on Labour party political broadcasts until the mid-1970s. He did this through DNA, with which I got my break into film production and directing.

His marriage to Jennifer ended in divorce, and in the early 80s David moved to the Midlands to work as a series producer on England Their England, a long-running series of half-hour film documentaries about the Midlands produced by ATV and Central TV. In 1986 he helped set up the film production company Waterside Productions, where he continued to support emerging film-makers hone their craft. David’s editing credo was: “Always be true to the rushes.”

In 1983 he married Dzidka Wiorkowska, a film editor, and they had a son, Tomek. Dzidka died of cancer in 1995, and David focused on raising Tomek while continuing to work as a producer and director in Birmingham.

Returning to London in 2010, David kept active by going regularly to the cinema, visiting the Frontline club and following Crystal Palace.

He is survived by his children and by seven grandchildren.