Britain's Prince Philip dropped an F-bomb during a photo opportunity at a London reception to mark the 75th anniversary of the Battle of Britain.

Us Weekly reported his grandson Prince William appeared to be suppressing a smile as the 94-year-old Duke of Edinburgh uttered the obscenity.

"Just take the [expletive] picture!" Philip growled as a photographer tried to organize a group portrait with Philip, William and the six surviving members of the Royal Air Force, who piloted planes in the Battle of Britain.

The elder royal has been married to Queen Elizabeth II since 1947.