Britain's Prince William and his wife Catherine, Duchess of Cambridge, speak with dignitaries as they tour the base of Emirates Team New Zealand, for the America's Cup World Series, at the Royal Naval Dockyard in Portsmouth, Britain July 26, 2015. [Photo/Agencies]

LONDON?- Britain's Mail on Sunday says it has uncovered a major royal security breach by using an inexpensive app to track Prince William's air rescue ambulance while it is in the air.

The paper said the 2.99 pound ($4.65) app allowed it to keep close track of William as he flew in his capacity as a private pilot with East Anglian Air Ambulance in eastern England.

It published photos claiming to show William's helicopter landing and of the prince himself.

The paper said Sunday that William's helicopter flies at low altitude at a relatively slow speed.

William's press office refused to comment on the report. The prince returned to work several weeks ago after paternity leave.