Between October 2017 and April 2018, three working dogs and two buzzards died as a result of poisoning in and around the Edradynate and Pitnacree estates area in rural Perthshire.
A Police Scotland Wildlife Crime Liaison Officer said: “The owners are understandably extremely upset at the loss of their dogs.
“Once again, we also find ourselves investigating the illegal killing of raptors and this is extremely disappointing.
“The poisons which have been used in both cases are illegal poisons and have been banned from use in the UK for many years.
“We have searched the areas and our investigations to date would suggest that there is not a wider threat to public safety.
“However, all members of the public in the area are asked to remain vigilant and report any suspicious behaviour, especially during the hours of darkness.
“Anyone with information that may assist our inquiries should contact Police Scotland on 101 or call Crimestoppers anonymously on 0800 555 111.’