Police have searched an estate in Perthshire after two poisoned buzzards and poisoned bait were found last month.
Tayside Police said the search of the estate, which has not been named, was part of an ongoing inquiry into the discovery of the dead birds of prey.
The operation got under way at 0800 BST on Wednesday with a number of homes searched under warrant.
All birds of prey are protected by law in Scotland.
Officers from the National Wildlife Crime Unit, the RSPB, and the Scottish Government Rural Payment Inspections Directorate also took part in the search.
Detectives said that a 62-year-old man was taken in to Tayside Police's divisional headquarters in Perth for questioning, but was later released pending further inquiries.
A number of items removed from the estate will now undergo forensic examination and testing in a bid to establish whether banned pesticides had been used or if any other offences had been committed.
Alan Stewart, wildlife and environment officer with Tayside Police, said: "Three weeks ago we found two poisoned buzzards and poisoned bait on the estate and inquiries are now ongoing to establish the source of the poison used.
"All birds of prey in Scotland, such as sea eagles, golden eagles, kites, buzzards and peregrine falcons, are protected by law and it is illegal to kill them or disturb their nests.
"We try our best to stop people from using poison."
He added: "Most pesticides used to kill wildlife are extremely toxic to humans as well as animals or birds and anything suspected to be bait or the victim of poisoned bait should not be touched."