A bodyguard for British Foreign Minister Dominic Raab was suspended from duty after leaving his gun on his flight back from the United States.
A cleaning officer discovered the Glock 19 semi-automatic pistol on the United Airlines seat, after the plane landed at Heathrow airport, London, on the morning of September 18.
"For some reason, he took off the holster with the pre-loaded Glock pistol inside and put it on the chair," said a source.
A London police spokesman confirmed today on the flight from Washington, US, to the UK and is "taking this issue very seriously".
Related bodyguards have been suspended from duty and an internal investigation is ongoing.
The British Secretary of State visited the United States in the middle of this week and held talks with Secretary of State Mike Pompeo and House of Representatives Speaker Nancy Pelosi.
British police in February also investigated the fact that a bodyguard of former prime minister David Cameron left a gun in the toilet on a flight from New York to London.