A man has been arrested at Buckingham Palace on suspicion of possessing a Taser.
Police were called to the visitors' entrance at around 12.45pm on Sunday after the man was detained by security staff.
The 38-year-old was arrested on suspicion of possessing a firearm, namely a Taser, and was taken into custody at a police station in central London.
Buckingham Palace declined to comment on the incident.
The Queen is currently at Balmoral Castle in Scotland on her summer break.