Defra confirmed today that the latest strain of bird flu is the highly pathogenic type, H5NI, as the cull of 6,500 birds started on a Suffolk farm.Fred Landeg, acting chief veterinary officer, said that the type found in the free-range turkey flock at Redgrave Park Farm, Redgrave, near Diss, was “of Asian linage.

Defra confirmed today that the latest strain of bird flu is the highly pathogenic type, H5NI, as the cull of 6,500 birds started on a Suffolk farm.

Fred Landeg, acting chief veterinary officer, said that the type found in the free-range turkey flock at Redgrave Park Farm, Redgrave, near Diss, was “of Asian linage.”

He told journalists in London this afternoon that the slaughter of the free-range turkeys, 1,000 ducks and about 500 geese, had started and would take some considerable time.

Samples would also be taken from the slaughtered birds in order to check how many were infected. Dr Landeg also said that while heavy mortality in the turkeys had been found, no other geese or ducks had apparently died from the H5N1 strain.

He also revealed that the virus strain was linked to outbreaks in wild birds in the Czech Republic and Germany. “The initial sequence data suggests that it's closely related to outbreaks in the Czech Republic and Germany, which does suggest a possible

wild bird source.

He said that although there was a large lake, with waterfowl, within 250 yards of the outdoor enclosures, Defra staff are keeping an open mind. “At this stage we are looking with an open mind as to the origin and all potential sources of the origin will be investigated.

Dr Landeg admitted that the site was particularly “challenging” and that a priority before starting the cull had been the protection of the staff. All had been given anti-viral treatments purely as a precaution.

Since the outbreak was confirmed yesterday, Defra immediately responded by imposing a 3km protection zone and a 10km surveillance zone. All movement of poultry had been banned within the zones.

As a further precaution, most of Suffolk and three district council areas in Norfolk - Norwich, Breckland, South Norfolk - had been placed within a restriction zone. In this area, poultry keepers have to either house their flocks or isolate them from any contact with other wild birds.

In February this year, a case of the same deadly strain of H5NI had been found in turkeys at Bernard Matthews turkey farm at Holton, near Halesworth. A total of 159,000 half-grown turkeys had been killed as part of the strategy to contain and prevent further spread of the virus. It was later confirmed that the most likely source of the infection was from Hungary when partly-processed meat had been imported.

The alarm was raised on Sunday after a rise in death rates among the birds, which are owned by poultry producer Gressingham Foods, based in Woodbridge.

The site's operations director Geoff Buchanan said about 60 turkeys in a flock had been found dead in one of five flocks

of 1,000 on Sunday. The firm had immediately called in the firm's vet, who alerted Defra's Animal Health and samples were taken. Yesterday, it was confirmed that it was the H5 strain but the exact type.

Defra has cancelled all bird gatherings, fairs and markets for poultry. Also all pigeon racing has now been cancelled as a further precaution.

IF there is an suspicion of animal health issues involving poultry - 0844 88 44 600.

Defra helpline - 08459 33 55 77 (Monday to Friday 6am to 10pm

For details, www.defra.gov.uk

Or www.suffolk.gov.uk