How AI is Helping Documentaries Protect Sensitive Contributors While Staying True to Authenticity
At first glance, documentaries and artificial intelligence might seem incompatible. The quest for truth through artifice appears contradictory, with early attempts—such as cloning Anthony Bourdain’s voice—drawing significant skepticism. However, as AI technology has progressed, filmmakers are increasingly integrating it into their storytelling, particularly using avatars to protect the identities of sensitive contributors.
This innovative approach was effectively showcased in the 2023 documentary Another Body, directed by Sophie Compton and Reuben Hamlyn. The film chronicles the experiences of a college student seeking justice after falling victim to deepfake pornography. The contributor’s identity remains concealed until about 15 minutes into the film, a narrative choice that underscores the impact of deepfake technology.
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More recently, UK network Channel 4 explored AI anonymization techniques in Kill List: Hunted by Putin’s Spies. Additionally, Netflix employed this technology in its documentary The Investigation of Lucy Letby, which garnered substantial media attention due to the contentious nature of the case surrounding convicted baby killer Lucy Letby.
Netflix began the 90-minute documentary with a disclaimer stating that “contributors have been digitally disguised to maintain their anonymity.” Among the interviewees were the mother of a child killed by Letby and a former friend of the nurse, both of whom shared emotionally charged testimonies behind AI-generated masks. The uncanny nature of these representations prompted a variety of reactions on social media.
Produced by ITN Productions, The Investigation of Lucy Letby credits Deep Fusion Films with the “identity protection” work, although Netflix has not actively promoted this aspect. Deep Fusion, a UK-based AI firm, is known for creating a podcast presented by the late chat show host Michael Parkinson and features a video on its website explaining its anonymization techniques.
The company touts a “4K, 10-bit, HDR likeness replacement workflow” that overlays a new identity and voice onto original footage, preserving the contributor’s emotional nuances and body language. Netflix has not confirmed whether this specific process was used in The Investigation of Lucy Letby, but it has previously stated that masking was performed with participant consent to ensure their anonymity, whether requested or mandated by court order.
Deep Fusion’s co-founder, Benjamin Field, refrained from commenting specifically on the film but engaged in a broader discussion about anonymization. He expressed concerns regarding traditional methods of identity protection, stating, “Their truth is never actually heard because it always has to go through a filter.” Field advocates for the use of digital doubles, arguing they allow viewers to perceive emotional subtleties often lost in traditional anonymization techniques.
Field explained that Deep Fusion aims to empower contributors by enabling them to curate the appearance and sound of their AI-generated personas. He also emphasized the importance of transparency regarding AI use in filmmaking, noting, “Audiences aren’t stupid. The more information you give the audience, the better things are received.”
Rachel Antell, an experienced documentary filmmaker and co-founder of the U.S.-based Archival Producers Alliance (APA), supports the use of masking to foster emotional connections between viewers and interviewees. Referring to the APA’s AI guidelines, she stresses the importance of “rolling consent” from contributors and calls for a more transparent approach that might include visual cues within the documentary to signify masked interviews.
Antell cautioned filmmakers about the risks of using AI tools, particularly given the opaque nature of large language models. “One of the things you’re dealing with all the time is this black box quality of AI,” she explained. This dilemma presents a significant challenge for journalists aiming to present verified information.
The ultimate measure of acceptance for these anonymizing techniques lies with viewers. Early uses have raised concerns, reinforcing Field’s observation that “audiences generally don’t think AI is cool.” Field humorously recalled being dubbed a “digital meat puppeteer” for his work on A Life Uncharted, which featured the recreation of Thunderbirds creator Gerry Anderson. However, he believes that as technology evolves, audiences may begin to appreciate AI’s potential to enhance authenticity.







