In the last few years, 11 people allegedly tied to top secret US research have died or mysteriously disappeared, sparking a conspiracy that a clandestine operation is silencing those who know too much.As Phil Tinline explains to Nosheen Iqbal, what began as a series of unrelated tragedies has morphed into a mainstream obsession and even triggered a federal investigation.However, there’s more to the missing scientists conspiracy than meets the eye. In fact, you can trace its roots back to a strange episode of Science Report that aired in Britain in 1977. Photograph: Anglia Television