A UK newspaper claims to have discovered a security breach related to Prince William’s work as an air rescue ambulance pilot.

The Mail on Sunday reports that it has been using a smartphone app to monitor the activity of the helicopter flown by Prince William. The paper claims that a $4.65 app is capable of tracking the aircraft while it is in the air, according to the Associated Press.

App Tracking Prince William Flights Is Terror Risk, Says Paper

Flight tracking app monitors helicopter flown by Prince William

Prince William currently works as a private pilot with the East Anglian Air Ambulance in eastern England. The app apparently allowed journalists to find out exactly where William would land the helicopter, constituting a considerable security risk for the royal.

A series of photos published by the paper apparently show William’s aircraft landing, and the prince talking to fellow air ambulance staff. The Mail on Sunday also claims that users who pay a small extra charge can receive a notification each time the helicopter takes off on a mission.

The newspaper emphasized the threat to William’s safety, and claimed that the Prince could have been an easy target for a terror attack.

Expert plays down security threat

Although it would be easy to modify the software so that the helicopter William uses is not tracked, it may not be necessary to do so, air safety expert Christopher Yates told The Associated Press. Despite the tracking capabilities and the fact that William reportedly does not fly with a protection officer, Yates does not see a threat.

“Most of the time when an air ambulance is called it appears on the scene, scoops someone up and disappears,” he said. “If there were someone monitoring, the chance of them being there at the scene when he arrives is quite remote. And we don’t know from one day to the next if he’s going to be on board. So I don’t see a problem.”

Prince William’s press office said that it was a security matter and refused to comment, nor did the Metropolitan Police. After a brief period of paternity leave after the birth of Princess Charlotte, William started back at work a few weeks ago.

William is an experienced pilot, and used to carry out similar rescue missions during a sting at a Royal Air Force base near the Welsh coast. However the perceived security threat is a new one; those military flights were not tracked by smartphone apps.