THE BURNED OVER DISTRICT

But the Brits still have the edge on panache when it comes to cloak and dagger work. Nevertheless the police aren't too good at covering up the wet work.

The bizarre death of a British intelligence analyst whose body was discovered inside a sports bag in a bathtub was called a probable accident by the London police on Wednesday, an inconclusive ending to one of the most puzzling investigations in recent years.

Gareth Williams, 31, a Welsh-born mathematician involved in code-breaking work, was found dead on Aug. 23, 2010, by police officers who entered his London apartment. His naked body was curled in a fetal position inside a sports bag in an otherwise empty bathtub. In a twist worthy of a spy movie, the bag was padlocked, but the keys to the lock were inside the bag, beneath the decomposing body.

Mr. Williams had evidently led a private existence, with few close friends. But with its tantalizing glimpse into the secretive world of espionage, the “spy in a bag” case drew intense interest from the news media, which speculated that Mr. Williams might have been killed, or might have died as an accidental consequence of an interest in escapology or bondage.

A post-mortem examination failed to identify a cause of death. A coroner’s inquest in 2012 found that someone else was probably involved in the death. However, the police now say they believe that Mr. Williams was most likely alone and locked himself in the bag, though they cannot rule out the possibility that someone else was present.

“From the inquest, we set up our investigation in a different way, and this has led to greater clarity on some aspects of the case,” Deputy Assistant Commissioner Martin Hewitt, who oversaw the police investigation, said in a statement. “Now, at the end of our investigation, based on the evidence, or where we have been unable to find positive evidence, we believe that it is a more probable conclusion that there was no other person present when Gareth died.”

After three years of investigation, Mr. Hewitt said, “many questions remain unanswered.”

The biggest question is how they believe anybody would believe this conclusion.