The royals' estate at Sandringham has been linked to the deaths and disappearances of multiple protected species of bird.
Rural police have been probing 18 cases of birds of prey found shot or poisoned, or which have gone missing over the past 20 years.
The 20,000 acre estate and surrounding farmland, also owned by the King, has been investigated in relation to 18 cases, documents obtained by The Guardian show.
