Police Scotland have described the unlawful poisoning of birds of prey in Dumfries and Galloway as "outrageous".
A growing number of red kites, which are a protected species, have been found dead in and around the Stewartry area.
Due to their scavenging nature the birds are vulnerable to poisoned baits, and it is thought that the chemicals used may also be harmful to other animals and humans.
Officers have described the poisonings as "illegal and totally unacceptable".
The birds were originally reintroduced into Dumfries and Galloway in 2001 and the Galloway Kite Trail, which is a partnership project led by RSPB Scotland, was launched in 2003.
The Kite Trail, which hundreds of tourists visit to see the birds being fed, has brought millions to the local economy.
Experts are concerned that the illicit killings are happening more frequently and in close proximity to where they are working to increase species numbers.
Police are working with local authorities to "put a stop" to the problem before anymore animals are harmed.