The controversy that erupted when Queen Elizabeth II's trusted art historian Anthony Blunt was exposed as a Soviet spy. As well as being close to the Queen, Blunt also worked for her father George VI and was a third cousin of the Queen Mother. It is rumoured that as a trusted insider, he was tasked by the King to help clean up evidence of potentially damaging stories about the royal family. But as the documentary reveals, it seems that royal insiders knew the truth about Blunt's treachery long before it was made public