STAFF at Abbotsbury Swannery are praying that birds there are building up an immunity to deadly bird flu.

No more dead swans have been found in the area since two tested negative for the H5N1 strain before the weekend.

The total number of dead animals there remains at nine since bird flu was confirmed last week.

Abbotsbury Tourism general manager John Houston said: "This is a step in the right direction for these wonderful animals to be saved for everyone to see in the spring.

"Thankfully no more dead swans have been found but obviously checks will continue at first light today.

"The last two negative results were very encouraging. But this is still very early days."

He added: "There might be a situation where the swans build up an immunity to the virus and are no longer affected.

"That is something we would hope to grow into and this is an encouraging first step."

Dead swans found along the Fleet have undergone testing for H5N1 since the first outbreak of bird flu in the UK about two years ago.

Three infected swans were discovered on December 27, 31 and January 4.

Mr Houston said: "There is ongoing monitoring and we are searching the Fleet for any signs of sick or dead swans.

"The Department of Environment, Food and Rural Affairs will carry on collecting them and doing testing."

Last week farmers neighbouring the swannery hit out at Defra for the way the outbreak was handled and a delay in information. Since the outbreak a control area around Abbotsbury Swannery was established about 15 miles to the south-east, including Weymouth, Chesil Beach and the Portland Bill headland.

A larger monitoring area of about 20 miles includes Dorchester.

The discovery of H5N1 came a month after restrictions on poultry movement were lifted in Norfolk and Suffolk.

Bird carcasses have been tested at the Veterinary Laboratories Agency in Weybridge, Surrey.