On the eve of the publication of Lord Stevens's report into the death of Princess Diana, an investigation into allegations that she was murdered by the secret service.
An investigation into the suspicions that still surround the death in July 2003 of the government scientist and weapons inspector, Dr David Kelly.
An investigation whether the Oklahoma City bombing was the work of lone bomber Tim McVeigh, or whether there were others involved who are being protected in a government cover-up.
The Conspiracy Files delves into the final mystery of 9/11: a third tower at the World Trade Centre, which along with the Twin Towers, also collapsed that day.
A decade after the attacks on New York, Washington and Pennsylvania, the Conspiracy Files looks at why some people still question what really happened on 9/11.