Pc Adams joined the Met in 1994

The body of Pc Amoreena Adams, 32, was found in the basement of the Territorial Policing Headquarters, at Victoria Embankment, in August 2004.

Dr Paul Knapman recorded a verdict that Pc Adams killed herself at Westminster Coroner's Court on Wednesday.

Pc Adams, who joined the Met in Barnet, north London, in 1994, was an armourer in the Diplomatic Protection Group.

The court heard Pc Adams had been "frustrated" after losing her authorisation to use arms two months before her death.

I think, quite clearly, she was depressed, and moderately disturbed, more than anybody had any idea Dr Paul Knapman

She had lost her licence once before but regained it and hoped she would be able to do the same again.

Colleague Sergeant Michael Robinson said Pc Adams was working at the time as a "non-shot" - issuing weapons to officers who needed them or searching vehicles going into Downing Street.

A close friend also said the officer would often get "down" in August as her father had killed himself at that time in 2001 and her 14-year-old brother died in the same month in 1990.

Dr Knapman, the Inner West London Coroner, said: "I think, quite clearly, she was depressed, and moderately disturbed, more than anybody had any idea.

Death investigated

"It is a tragedy, as it happens, that she had the mechanism to commit suicide by this method."

A police-issue Glock 9mm self-loading pistol was found by the side of the officer.

She joined the team, which protects diplomats in London, in December 2001 and was based at Canon Row police station.

The death was investigated by the Specialist Crime Directorate, Scotland Yard said.