Wild birds may have been behind Britain's recent bird flu outbreak, the government believes.

The Department for the Environment, Food and Rural Affairs' (Defra) preliminary epidemiological report into the East Anglian bird flu outbreak did not uncover any evidence that the virus was introduced through poultry or poultry-infected products.

As a result molecular genetic findings indicate wild birds may have introduced the H5N1 strain into Suffolk from Europe, it suggests.

"The continued surveillance may help clarify the infection status of the wild bird population, but we have no evidence of high levels mortality in the local wild bird populations which would suggest a high prevalence of H5N1 infection in these populations," the report noted.

It added its preliminary findings showed a free-range poultry unit was likely to attract wild birds because of the availability of its feed.

Poor biosecurity measures were also found to be in place on the farm.

The Royal Society for the Protection of Birds (RSPB) launched a stinging attack against the report, criticising the government for dismissing the likelihood of a commercial turkey or duck being responsible.

It said the government had taken too long to employ bird scaring and soil disinfection measures which it had recommended six days ago.

"There have been no cases of bird flu in wild birds in the UK or western Europe since August and the source of the Suffolk outbreak remains a mystery," conservation director Mark Avery said.

"It is staggering that Defra has taken almost three weeks to take action to prevent wild birds becoming the latest victims of the disease."
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