LONDON — An inquest into the death of a British codebreaker whose naked and decomposing body was found inside a padlocked sports bag will look into whether spy agencies were involved in his death.

Gareth Williams worked for Britain's secret eavesdropping service GCHQ and was attached to the country's MI6 overseas spy agency when he was found in the bathtub of his central London home in August 2010.

There were no signs of struggle, and no drugs or poison in the 31-year-old's body, the discovery of which launched a media frenzy and flurry of conspiracy theories.

Detectives have suggested Williams may have died in a sex game gone wrong, but Williams' family told a pre-inquest review in March that they do not accept a claim by British authorities that his death was unconnected to his work.

Their lawyer, Anthony O'Toole, said at the time that the family believe an "unknown third party" specializing in "the dark arts of the secret services" may have tampered with the scene where Williams was found, or interfered with other evidence that could help explain how he died.

The inquest, which begins Monday, will investigate whether Williams could possibly have climbed inside the sports bag and locked it from the inside.

In Britain, inquests must be held when someone dies unexpectedly, violently or from unknown causes. However, the coroner's task is to determine the cause of death, rather than to identify any suspect.

Police have made no arrests in the case and are still not certain how exactly Williams died. Toxicology tests confirmed there were no traces of known drugs or poisons in his system, and experts consulted by police said Williams could not have locked himself inside the bag.