Key dates surrounding spy's death

This is a timeline of key events in the investigation into MI6 codebreaker Gareth Williams's mysterious death.

2001

:: Mr Williams, a maths prodigy from Anglesey, north Wales, joins GCHQ, the British national security agency responsible for intercepting and decoding signals intelligence.

2009

:: He is seconded from GCHQ to MI6, the UK's foreign intelligence service.

2010

:: August 11 - Mr Williams returns to Britain from a fly-drive holiday to the West coast of the United States.

:: August 15 - He is captured on CCTV in London's Knightsbridge after shopping at the luxury Harrods department store.

:: August 23 - Mr Williams' decomposing naked body is discovered padlocked inside a large North Face holdall in a bath in his top-floor flat at 36 Alderney Street in Pimlico, half a mile from MI6's headquarters in the capital.

:: September 1 - Westminster Coroner's Court hears that a post-mortem examination has failed to establish the cause of the codebreaker's death as his inquest is opened and adjourned.

:: September 24 - Sir John Sawers, the head of MI6, attends Mr Williams' funeral at the Bethel Methodist Chapel on Anglesey.

:: October 28 - Scotland Yard says toxicology tests have found no traces of drugs, alcohol or poisons in the spy's bloodstream.

:: December 22 - Detectives reveal that Mr Williams repeatedly accessed bondage websites, visited London gay bars, and had several wigs and £15,000 worth of unworn designer women's clothes in his wardrobe.

Police also say it would have been impossible for him to lock himself in the holdall in which his body was found.

2012

:: March 30 - A pre-inquest review hears that Mr Williams' family suspect an agent specialising in the "dark arts" may have covered up his death.

The hearing is also told that detectives spent 18 months investigating a DNA sample found on the spy's hand before discovering it came from a forensic scientist involved in the case.

:: April 23 - The inquest into Mr Williams' death begins.