Based on a comprehensive investigation into the nature and evolution of the global rendition system, this paper seeks to provide an account of the extent of British involvement in and knowledge of that system. It shows that UK authorities have been complicit in a wide range of human rights violations associated with rendition, secret detention and torture. Using Stanley Cohen’s framework for explaining how states deny involvement in and knowledge of atrocities we demonstrate the various ways that the UK government sought to cover up both its knowledge of the system, and its role within it. The paper is also aimed at offering some insights into how we have undertaken the research into these highly secretive practices. The paper begins by setting out the key elements of the global rendition system. It then explains how each of those elements violates various human rights conventions before going on to examine the extent of British involvement, and the lengths the British government went to in denying both knowledge of the system and complicity in it