One of the Queen's swans was apparently "barbecued" and left on a river bank near Windsor Castle, an animal charity has said.
The bird was butchered and stripped of its flesh before its carcass was dumped
close to the water on Baths Island in Berkshire.
Wendy Hermon, 46, of the charity Swan Lifeline which cares for sick and injured birds, said she discovered the "sickening" scene on Sunday afternoon.
"It was just a carcass, it was all burnt. "It was done neatly, presumably to get at the meat."
"We have no idea how it was killed, it could have been shot or beaten."
All wild mute swans in Britain are considered to be the property of the Crown and it is an offence to kill one.