Forty dead pigeons have been found floating in Peterhead harbour after possibly being dumped.
The Scottish SPCA said there were earlier reports of as many as 100 being in the water at Albert Quay on Monday.
Three of the recovered birds are to have post-mortem examinations in a bid to establish the cause of death.
Senior inspector Scott Elphinstone said: "There were bags and boxes reported floating nearby which suggests the birds may have been dumped."
A member of the public had raised the alarm.
The Scottish SPCA inspector said: "On arrival at Albert Quay I counted a total of 40 dead pigeons in the water, although the gentleman who contacted us estimated there to be around 100, so others may wash up elsewhere.
"Disposing of animals in this manner is not only inappropriate but it also poses an environmental risk in terms of pollution, particularly as we do not yet know the means by which these animals were killed.
"We should have a clearer idea of what happened to them within the week."
He added: "I'd urge anyone who knows anything about this incident to contact our animal helpline on 03000 999 999."
The Department for Environment, Food and Rural Affairs (Defra) has been made aware of the incident.