A former police commissioner resigned after attempts to expose rape and torture by British colonial forces in Kenya during the Mau Mau uprising were covered up, a documentary shows. During the 1950s, Britain fought a war in Kenya against the Mau Mau, a movement that fought for independence from colonial rule. The movement was brutally suppressed through the use of widespread detention camps and systemic violence. Though successive British governments have attempted to distance themselves from the violence that unfolded, the documentary, which airs on Channel 4 on Sunday at 10pm, shows how Britain was not only involved in a regime of systematic torture – including allegations of murder, rape and forced castration – but took steps to suppress evidence. The documentary, titled A Very British Way of Torture, pieces together many of the worst abuses committed by British colonial forces through survivor testimony and expert analysis from a team of British and Kenyan historians. It also delves into an archive that had remained hidden for more than 50 years in a facility used by MI5 and MI6. Among new evidence is a previously secret letter from the commissioner of police for Kenya, Arthur Young, which reveals the truth behind his resignation. Young, who was previously working for the Metropolitan police, was dispatched to Kenya to investigate alleged abuses. Young quickly began to uncover instances of human rights abuses, which involved colonial officers either carrying out the alleged violence or trying to cover it up. Young presented these cases to the ministry of legal affairs in Kenya and the attorney general, but the investigations were ultimately blocked. He then resigned in a scathing letter that criticises the administration in Kenya and the UK for preventing him from doing his job. His resignation letter was kept out of the public record and a toned down version was published instead. “It goes to show the wider process by which the British government, together with the colonial administration, tried to stop people from discovering what people within the police knew was happening and knew was wrong,” said Niels Boender, a historian from the University of Warwick who researches this period for the Imperial War Museum, which helped with the research and features in the documentary. “You often hear people say in Britain that it was acceptable by the standards of the time. And I think documents like this really illustrate that, no, people at the time knew this was wrong as well. It was a specific effort by people in the government and people in the colonial state to conspire to keep that out of the public record. That finding of the documentary is very significant,” he added. The documentary also uncovers fresh details about the governor’s complaints committee, a shadowy body in the Kenyan administration that the film shows was one of the chief mechanisms for suppressing allegations of torture. Boender describes the documentary as “striking” in exposing the violence that occurred under the British empire. He believes there is a disconnect between the research and conversations that occur between historians about the empire and the current public debate. “You find that the debate is sort of stuck, what in my opinion is 50 years in the past. In the public level, the debate is ‘was empire good?’, whereas we’re kind of debating well, how bad was it and in what ways was it bad. The entire discussion is occurring on a different plane,” he said. “There’s actually only a very tiny group of historians that make this sort of ‘remember the railways’ sort of arguments, but they have a completely disproportionate hold on the public imagination. “Documentaries like this can shift the balance.”