Five missing swans may have been stolen and decapitated.

The birds are believed to have been taken from Provanhall House in Glasgow at the end of June.

A swan's head was later found nearby by a member of the public.

Inspector Stacey Erwin said: "We believe that whoever is responsible has removed five swans from Provanhall House Loch and Bishop Loch.

"Swans can be lured over by slapping the water. We suspect these birds may have been netted and then removed from the water.

"This is a very serious and cruel act and we are keen to find the person responsible.

"We're encouraging the public to be aware of any suspicious goings on around Bishop Loch and Provanhall House and to report any information to our animal helpline."

Several incidents where swans were stolen to be eaten have been reported in England, although the Scottish SPCA was not aware of any in Scotland.

While the Queen has the right to claim ownership of certain types of swan living on the Thames, that power does not extend to Scotland.