The MI6 officer took his “Houdini games” too far when he was locked in a large sports bag at his flat.
Williams, 31, stripped naked and climbed into the sports bag in his bath, armed with a padlock key.
Scotland Yard detectives believe he asked someone to snap the padlock shut on the bag’s zip and leave him to find his own way out. But the lock was on the outside of the bag and he could not reach it. With little oxygen in the sports bag, he soon passed out and suffocated.
Officers are still looking for a mystery couple seen at his flat who could explain how the padlock on the bag was snapped shut.
It is still not clear whether anyone was in the bathroom when the spy started struggling for air. Williams may have told the person to leave the flat after locking him in the bag to add to the asphyxiation “sensation” and the feeling that he was dicing with death.
The codebreaker was found dead in the bath at his flat in Pimlico, central London, on August 23. He had been there for up to eight days.
Police checks on his laptop computers uncovered links to weird websites, including one called Torture Garden which deals with fetishes like claustrophilia.