LONDON (AP) — London’s Metropolitan Police are investigating after former Prime Minister David Cameron’s bodyguard reportedly left his gun in an airplane bathroom.

The Daily Mail newspaper reported that the weapon found on a trans-Atlantic flight was handed to flight attendants. The Sun reported that passports belonging to Cameron and the officer were also found.

Police said they were aware of the matter that took place Monday and that the officer involved has since been removed from operational duties.

“We are taking this matter extremely seriously and an internal investigation is taking place,” police said in a statement.

As a former British prime minister, Cameron is entitled to security provided by a specialist police unit.