The bird which The Herald reports was found on the North Glenbuchat Estate, in Strathdon, Aberdeenshire at the end of March and subsequently tested positive for the banned pesticide Carbofuran.

Grampian Police, along with officers from the Scottish Government Rural Payments and Inspections Directorate (SGRPID), carried out a joint operation, which also involved personnel from Tayside Police, National Wildlife Crime Unit, RSPB and SSPCA, at the estate.

Constable David MacKinnon, (right) force wildlife crime officer, said: “Our efforts in Scotland and Grampian to eradicate this type of crime over a number of years have been challenging and clearly we still have some way to go.

Bob Elliot, (left) head of investigations at RSPB Scotland, said: “This highly toxic chemical, which it is illegal to possess, was found to have poisoned this golden eagle. Poisoned baits lying out in the countryside are indiscriminate and threaten both pets, domestic livestock and even humans.

“That such potentially lethal activity continues in this day and age is an outrage, and threatens the international reputation of Scotland as a haven for wildlife and iconic species.”

Last year more than 200 of Scotland’s leading landowners wrote to Environment Minister Roseanna Cunningham denouncing the poisoning of birds of prey.

The Langholm Moor Demonstration project launched in September 2007 and running for 12 years is aimed at resolving the conflict between grouse moors and harrier populations, it being well known that carcasses treated with poison are left on hillsides to reduce the rarer raptor populations that feed on the grouse chicks, integral to sporting estates.