There are fresh fears that avian flu is spreading further in the wild bird population following reports that sedentary birds are being found on beaches and make no attempt to move away when people approach.

Recent winters have seen poultry keepers having to take special measures to keep flocks indoors over fears of the disease spreading to farmed birds.

The latest casualty was discovered by Simon Tucker at Freshwater East in Pembrokeshire.

“It was a gannet,” he said. “While it looked healthy enough, it just wasn’t moving whenever anybody approached it, and with bird flu hitting a colony on one of the nearby islands, I felt it important to pass the information on.”

Two more dead birds, namely a gull and an egret, were discovered on the rocks at Newgale over the weekend.

Earlier this month, RSPB Cymru confirmed that dozens of gannets had been found dead on Grassholm Island following an outbreak of the highly contagious avian flu.  They also stated that the colony of 36,000 pairs of gannets could be completely wiped out as a result.

Grassholm currently contains the world’s third largest gannet colony and is one of only two gannet sites in the whole of Wales.

"This has the potential to be really serious as it’s a highly contagious strain that jumped from the poultry industry in south-east Asia into the wild bird population,” said the RSPB’s head of species, Julian Hughes.

And as birds migrate, the strain of avian flu - H5N1 - has subsequently been carried all over the world.

"To find a few dead birds is not uncommon, but when we returned to Grassholm at the beginning of August we continued to find even more, and that was when we sent them to be tested.

"Sadly this could now turn into hundreds ofthousands."

The disease is spread through the birds’ guano and a large part of Grassholm is carpeted with it, just as on Skomer and Skokholm Islands.

Typically this form of the disease is difficult to detect and presents itself very suddenly.

Affected birds may develop swollen heads, a blue colouration of the comb and wattles, dullness, lack of appetite, respiratory distress, diarrhoea and significant drop in egg production.

Meanwhile the RSPB is urging people not to touch any dead or dying birds which they may find on the Pembrokeshire beaches. Dogs should also be prevented from picking them up.

Any dead or dying birds should be reported to DEFRA on 03459 335577.