Allan Segal: Bafta-winning film-maker who worked on 'Horizon' and 'World in Action'

Allan Segal, who has died aged 70 after a nine-month fight with cancer, was one of a generation of young producers who brought a new era of tough, investigative journalism to British television in the 1970s and 1980s.

Born in Reading in 1941, the eldest son of a London taxi-driver whose parents had emigrated to England from Eastern Europe at the end of the 19th century, Segal was brought up in a Jewish household in Southall, west London. He won a scholarship from grammar school to the London School of Economics in 1963. There, he spent as much time in the debating society as in lectures, already giving ample evidence of the combative skills he soon put into practice as a journalist.

After graduating in 1965, he went straight to the BBC TV Features department as an assistant. His earliest work was on the ground-breaking Horizon series, where he concentrated above all on the impact of scientific and technological change on British society.

He was soon poached by Granada, then at the forefront of challenging documentary-making. "I researched, produced and directed more than 20 films in Britain and worldwide," he recalled. "Some, because of their immediacy, were made at great speed; others, more in-depth investigations, took up to a year to complete. On occasions [they] necessitated the use of hidden cameras in hostile situations."

These challenging films were what most attracted Segal. In 1973 his film on a thalidomide victim My Son Kevin won the Blue Ribbon Award at the New York Film Festival. He followed this up in 1976 with another award-winning documentary, shot on 8mm amateur equipment in Brezhnev's Soviet Union, about a Jewish refusenik and his campaign to be allowed to leave for Israel. Hundreds of rolls of the two-minute films were smuggled out of the USSR to Finland on an Aeroflot passenger plane.

In 1978 Segal won his first Bafta award for the one-hour film Made In Korea, looking at how traditional British industries were being undercut by their competitors in South-east Asia. Soon afterwards, he became the executive producer for the hard-hitting documentary series World in Action. This weekly programme is still regarded by many as the model for investigative journalism on TV, and was recognised as such in 1998 when it was given the Judges' Award for an outstanding contribution to investigative journalism by the Royal Television Society.

As editor of World in Action, Segal became embroiled in a legal battle over his refusal to reveal the source for leaked documents that revealed misdeeds within the state-run British Steel Company. Although the courts ordered Granada to hand over the documents, Lord Denning claiming the matter was of grave national importance as only someone in the higher management of the company could have revealed such damaging information. Years later, Segal told the true story: "we were given the document in a loo in the basement of the Corby British Steel offices by a Socialist Workers' Party activist who emptied the wastepaper baskets there."

In the 1980s, Segal also collaborated on another prestigious series, Channel Four's End of Empire. Of the 120 TV films he made, the ones he shot on Kenya and India remained the work of which he was most proud. His travels for the series took him to India and Pakistan, which from then on became favourite places to return to, in particular the Jamia Millia University in Delhi, where he taught the history of documentary film. In the mid-1980s, Segal and his team undertook undercover filming in South Africa to make four documentaries on apartheid. He also contributed to the book on the series, which once again won him an award, this time the Broadcasting Press Guild's Best Documentary Series for 1986.

His greatest international success came at the start of the 1990s when he was editor for Dinosaur!, four hour-long films he wrote and edited for ITV in Britain and the Arts and Entertainment network in the US. Presented by the legendary Walter Cronkite, the series was credited with the highest viewing figures in the history of the network.

In 1988 Segal married the historian Jacqueline Fear, with whom he had two sons. He followed her to Norwich and UEA, where he taught on the Media and Society course for several years. He also became a dedicated local magistrate, often showing his well-hidden compassionate side when he talked of the generations of neglect obvious among the offenders he had to deal with on the bench. He continued to serve until his recent retirement at 70, when he was genuinely surprised and moved to learn of the esteem and affection in which he was held by his colleagues.

Allan Howard Segal, documentary film-maker: born Reading 16 April 1941; married 1988 Jacqueline Fear (two sons); died Norwich 8 February 2012.