An investigation has been launched after a royal protection officer accidentally fired a gun while guarding the Duke and Duchess of Cambridge's home.
The officer was sitting in a car with a colleague when they accidentally let off the shot while on duty in Anglesey, north Wales, last week.
No one was hurt and the bullet went into the floor of the car. The officer has been taken off firearms duty while the incident is investigated.
A Met Police spokesman said: "Shortly before 1pm on Wednesday October 24 an on-duty MPS police officer unintentionally discharged a firearm while in an unmarked police vehicle.
"The round damaged the floor of the vehicle. Another on-duty officer was in the vehicle at the time of the incident. Neither officer was injured. The officers were on duty in north Wales at the time."
The force was keen to stress that the officers were some distance away from the property at the time, and that no one else was at risk.
Prince William, or Flight Lieutenant Wales as he is known in his capacity as a RAF search and rescue helicopter pilot, captains Sea King helicopters from his unit's base at RAF Valley in north Wales.
Police would not comment on the type of gun, but royal protection officers routinely use 9mm Glock 17 pistols.
In June 2000 a royal protection officer accidentally fired two shots on the royal train while the Queen and Duke of Edinburgh were on board. No one was injured in the incident, which occurred in the early hours of the morning when the royals were asleep in another carriage.
And in November 2008 one of Tony Blair's bodyguards accidentally fired his gun as the former prime minister prepared to board a flight at Ben Gurion airport in Israel. No one was hurt in the incident, with the bullet hitting the ground.