A reward for information which helps catch those responsible for poisoning two golden eagles in Scotland has been increased to £10,000.
RSPB Scotland hopes the new reward will help catch the culprits
The birds died at the Glenfeshie Estate in the Cairngorms and the Dinnet and Kinnord Estate near Ballater in Aberdeenshire.
RSPB Scotland had pledged £2,000 to help catch the culprits, the first time in its history it had offered a reward.
Two anonymous donations have now upped the figure to £10,000.
RSPB Scotland said this showed the "public outrage".
The charity offered the £2,000 reward in August. It said the deaths, which took place in May and June, were "dreadful crimes".
It is understood that both birds were poisoned using illegal carbofuran poison. Possession of this substance is in itself a crime.
A businessman from Bath has contacted the charity and pledged an extra £8,000.
Another donor, from Scotland, said he would cover the charity's reward costs by paying the £2,000 already offered by the RSPB.
The donations mean £5,000 is now available for information that leads to a successful prosecution on each incident.
The unnamed donor from Wiltshire said: "I simply cannot believe anyone would wish to kill such a magnificent and awe-inspiring creature as a golden eagle.
"It is my hope this donation will serve as a reminder how abhorrent the vast majority of right-thinking people view this activity and help to stamp it out altogether."
Both birds were thought to be poisoned with illegal carbofuran
An RSPB Scotland spokesman said: "The fact that two people, both of whom were previously unknown to the RSPB and are not members, have been motivated to approach us is indicative of the public outrage at these crimes."
RSPB Scotland hopes the reward will highlight the serious nature of this type of crime, as well as underlining the RSPB Scotland and police determination to detect those responsible and bring them to justice.
Stuart Housden, director of RSPB Scotland, said: "Golden eagles are magnificent icons of the Scottish uplands.
"We should be proud that Scotland supports some 442 pairs of these awe-inspiring birds that attract tourists from all over the world.
"Yet some in our country selfishly persecute these birds, through the use of poisoned baits or other means. In the space of just three months, two dead eagles have been found - killed illegally."
Anyone with information can contact either Northern or Grampian police, Crimestoppers or the Campaign Against Illegal Poisoning of Wildlife on 0800 321 600.