Governments across Europe are being too hasty in blaming the spread of avian flu on wild birds, says the Royal Society for the Protection of Birds.
Hundreds of thousands of birds have been killed in Turkey
Many scientists say there is evidence wild birds are spreading the highly dangerous H5N1 strain of the virus.
But the RSPB says the trade in birds and the movement of poultry products is a more likely cause.
The charity said there are no migration routes that would take birds from China to Turkey at this time of year.
A spokesman for Defra said government scientists were monitoring the situation, including the migratory patterns of wild birds.
The World Health Organisation recently said viruses from Turkey's first two human cases were virtually identical to those that killed 6,000 migratory birds in a nature reserve in central China.
But the RSPB's conservation director Dr Mark Avery says that beyond doubt the trade in wild birds and the movement of poultry and poultry products, such as chicken manure used to fertilize fish farms, has led directly to the transfer of H5N1 across national boundaries.