London - A female Scotland Yard officer who once served as a bodyguard to ex-prime minister Tony Blair left her semi-automatic gun behind in the loo of a central London cafe, the police force said Thursday.

Confirming a report in the Sun newspaper, Scotland Yard said the incident, which happened on August 29, was being investigated.

The semi-automatic Glock 17 pistol was found by a member of the public in the toilet of a cafe of the Starbucks chain, where it had been lying for about 20 minutes.

The officer, in her 30s, had taken off the belt holding the firearm when she used the toilet and then bought a coffee, forgetting she had left the gun behind.

The pistol was eventually linked to her when police compared its serial number to those logged at a police armoury.

"A police-issue firearm was left unattended in a Central London cafe on August 29 and was found by a member of the public. The weapon belongs to a Metropolitan Police authorized firearms officer, who was on duty at the time," a Scotland Yard statement said. (dpa)