THE MI6 spy found dead in a holdall had illegally hacked into secret data on Bill Clinton, The Sun on Sunday can reveal.
Gareth Williams, 31, dug out the guestlist for an event the former American president was going to as a favour for a pal.
The codebreaker — who had breached his security clearance — handed the list to the friend, who was also to be a guest.
MI6 bosses raged over the data breach amid growing tensions with US security services over Mr Williams’s transatlantic work.
Today, just over five years since his body was found inside a padlocked bag, his death remains one of Britain’s most mysterious unsolved cases.
The Sun on Sunday can reveal that voicemail messages Mr Williams left for family and pals were deleted in the days after his death. And a rival agent may also have broken into the flat to destroy or remove evidence.
The inquest was barred from discussing Mr Williams’s work in public. But sources say he was helping on the joint monitoring network Echelon, which uses sophisticated programs to eavesdrop on terrorists and criminal gangs, particularly those in Russia.
Echelon is used by Britain, the US, Canada, Australia and New Zealand.
A source said: “The Clinton diary hack came at a time when Williams’s work with America was of the most sensitive nature.
“It was a diplomatic nightmare for Sir John Sawers, the new director of MI6 at the time.”