The bodies of seven dead ducks have been discovered strewn along a river bank in Grove.
Judy Gibbons found the dead birds beside the Letcombe Brook when she went to visit a friend in Sharland Close, off Cane Lane, on Tuesday.
Mrs Gibbons, from East Hanney, said: "I couldn't believe my eyes. It was carnage. There were seven large, dead ducks lying on the grass and some of them had blood on their bodies.
"I would have thought that if they had been caught by a fox or a dog they would have created the most horrendous noise."
Lucy Clark, an RSPCA spokesman, said a member of the public had suggested that a recycling collection lorry might have run over the ducks, but no witnesses had come forward.
Martin Litherland, of the Vale of White Horse District Council, said: "We have investigated the incident, but there's no evidence to suggest that one of our contractors' vehicles was involved."
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