Two young satellite-tagged white-tailed eagles have disappeared, according to the Royal Society for Protection of Birds (RSPB), which has not received a tag signal since 22 July.

The bird charity is “almost certain” the birds have been killed and have called the circumstances “highly suspicious”, with the eagles' last recorded movements over grouse moors in Invernessshire and Aberdeenshire.

However, Scottish Land and Estates has hit back, calling for more evidence to come forward before pointing “the finger of blame at grouse moors”.

Meanwhile, the RSPB states that the Invernessshire grouse moor is in an area with a “history of bird of prey persecution”.

First generation

The birds that disappeared in July were both from the first generation of chicks from breeding pairs in the white-tailed eagle population in east Scotland.

The RSPB Scotland’s head of investigations Ian Thomson said: “Yet again, rare, protected birds of prey have disappeared in highly suspicious circumstances, with their last known locations on grouse moors.

"And, yet again, we can be almost certain that these birds have been killed, with those responsible destroying all the evidence.

"The disappearance of these two eagles is more than a loss of two birds; it means any future breeding success they might have had, helping to boost the numbers of these rare birds, has also been destroyed.

'Illegal persecution'

"Illegal persecution is seriously undermining the re-establishment of a white-tailed eagle population in this part of Scotland.”

Executive director at Scottish Land & Estates Sarah-Jane Laing said: “Anyone with information should contact Police Scotland immediately.

“Landowners in both the areas where the birds were apparently last located are able and willing to help in the search. We wholeheartedly condemn any form of raptor persecution and firmly support tougher penalties for those found guilty of such crimes.

It is frustrating, however, that more than three months has passed before the appeal for information has been issued

“It is frustrating, however, that more than three months has passed before the appeal for information has been issued publicly by RSPB and we await further information from Police Scotland.

"We believe the more assistance can be given to find the bird, and where a crime has been committed then it would surely help increase detection and prosecution.

"We firmly believe that this would be aided by a more independent and transparent system of monitoring satellite-tagged birds.

“We question RSPB’s decision to immediately point the finger of blame at grouse moors rather than to find out what has actually happened. Last month, a tag fitted to a hen harrier in England stopped transmitting and an appeal for information quickly issued, with the bird eventually located safe and well following a tag malfunction.”

Both the National Wildlife Crime Unit and Police Scotland have already conducted investigations, but yielded no further information as to the eagles’ whereabouts.

Anyone with information about either of these birds or any other wildlife crime is urged to contact Police Scotland on 101.