M16 agent Gareth Williams was found dead by police officers inside a zipped bag at his London flat back in 2010.
There was lots of speculation about his mysterious death, with the most popular one suggesting that it might be linked to the secret intelligence work he carried out in his work as a Government Communication Headquarters (GCHQ) officer.
The mystery behind Williams' death has been explored in different documentaries over the years, including Channel 5's The Body In The Bag - which airs tonight - and Sky's Once Upon A Time In Londongrad.
