Two peregrine falcons have been found poisoned in Cornwall by a banned chemical.
Tests were carried out on the two birds of prey, after they were found in July, to see why they'd died.
The results have now confirmed that they were poisoned with a banned pesticide called Carbofuran.
Bird charity RSPB are offering a reward of £1,000 for information that helps find who did it.
Pc Jack Tarr, a wildlife crime officer in Cornwall, said: "That these magnificent birds should be killed in this way is truly shocking. We need to find out who did this and bring them to justice."
Peregrine falcons are specially protected and poisoning them is against the law.
Peregrine numbers declined over the last 200 years because they were killed illegally. Though their situation is better now, the birds are still vulnerable to persecution.