Jess Search, who has died aged 54 of brain cancer, did much to shape and inspire the world of documentary film. With the colleagues who had joined her in creating the non-profit organisation Doc Society, she sought to harness the power of non-fiction storytelling to bring about change on such issues as the climate crisis and defending democracy.

The many dozens of films she funded, advised, mentored, distributed, produced or executive produced include Citizenfour (2014), about the whistleblower Edward Snowden; Virunga (2014), on protecting gorillas in the Democratic Republic of Congo; The Look of Silence (2014), recalling the murder of a million supposed communists in Indonesia in the mid-1960s; Knock Down the House (2019), following the campaign in which Alexandria Ocasio-Cortez was elected to the House of Representatives; Cow (2021), a portrait of bovine life on the farm; and the Indian journalism exposé While We Watched (2022).

Jess found innovative sources of funding, enabling “impossible” films to be made, or deployed original campaign tactics to boost their influence. To promote Laura Poitras’s Citizenfour, for example, Jess and colleagues projected Trevor Paglen’s video artwork Code Names of the Surveillance State, exposing GCHQ codenames, on the side of the Houses of Parliament in a completely unauthorised stunt.

The vehicle for accomplishing all this started life as Britdoc, the UK’s first documentary foundation, which she co-founded in 2005. The organisation rebranded as Doc Society in 2017, and three years later it adopted a flat management structure shared between Jess and her colleagues Beadie Finzi, Maxyne Franklin, Shanida Scotland, Megha Sood and Sandra Whipham.

Their aim was to support “people who are able to make work that is completely uncompromising, without fear or favour”.

This led to them examining the wider ecosystem of non-fiction storytelling. Keen to establish the measurable impacts of film, they published their Impact Field Guide & Tool Kit. The sort of result they were looking for was how the account of overfishing in The End of the Line (2009) encouraged the supermarket chain Waitrose to stop the selling of swordfish.

A likeminded alliance of activists, storytellers and lawyers, the Bertha Foundation, joined them in establishing a journalism fund to support films and provide the first safety and security guidelines for filmmakers working on dangerous projects. Doc Society now has 30 employees, and the public role of administering the funds from the British Film Institute for making documentaries.

Working as a journalist, conference moderator and festival programmer, I had got to know Jess over the past 20 years, notably through Good Pitch, the forum that Britdoc established in 2009 to connect storytellers with NGOs, foundations, brands and community organisers. In the course of 58 editions, in countries from Argentina to Indonesia, and now run in partnership with the Ford Foundation and the Sundance Institute, it has enabled tens of millions of pounds to go into films.

Born in Waterlooville, Hampshire, and brought up in Sevenoaks, Kent, Jess was the daughter of Henrietta (nee Loufte), who went on to be an executive at MSI Reproductive Choices, and Phil Search, a businessman. He died in a car accident when Jess was 18.

From Tonbridge grammar school and Sevenoaks school she went to New College, Oxford, where in 1991 she gained a degree in philosophy, politics and economics.

After university, she spent a year immersing herself in Sydney’s gay scene. When she returned to the UK, her uncle Tony Laryea, a pioneering black broadcaster, invited her in 1992 to work for his production company, Catalyst Television. In 1998, she and her friends Cath Le Couteur and Stu Tily co-founded an online community called Shooting People to encourage and connect aspiring independent filmmakers. The community that started with 60 film-makers has now grown to 30,000 people.

The following year she joined Channel 4’s independent film and video department as a commissioning editor. When the channel had launched in 1982, it was a lifeline to her, “growing up queer and gender nonconforming in the suburbs”. She loved working at the arm of the broadcaster that was “experimenting with new voices”, including Lee Kern, who went on to create Celebrity Bedlam, and Andrea Arnold, the eventual director of Cow.

Jess was involved with the controversial programme My Foetus, whose showing was the first UK broadcast of an abortion, involving a woman who was four weeks pregnant. That came in 2004, the year that the department came to an end, and she and her colleague Franklin joined Katie Bradford and film-maker Finzi to create Britdoc, with backing from Kevin Lygo of Channel 4.

At industry events Jess thrived on stage in her trademark white suit, moderating with insight and sharp humour at Good Pitch and other international events.

Outside Doc Society she gained an MBA (2008) from Cass Business School and served on the boards of the Institute for Public Policy Research (IPPR), MSI Reproductive Choices (continuing the work of her mother), and the crowdfunding company Kickstarter.

In 2018 she married Beadie in Margate. They raised two children, Ella and Ben, and were active in the community, setting up a residents’ association. Their wedding had culminated with their guests marching in the Margate Pride parade.

Jess loved walking her energetic lurchers, reading poetry and gaming – particularly Grand Theft Auto and Minecraft. She continued to pitch for Doc Society funding into the last weeks of her life.

She is survived by Beadie, their children and her brother Dominic.

• Jess Search, documentary film producer and campaigner, born 15 May 1969; died 31 July 2023