Tests are being carried out on 30 birds in the West Midlands following fears they could carry the deadly HN51 strain of bird flu.

The birds were collected by the State Veterinary Service (SVS) over the weekend after it was inundated with calls from concerned members of the public.

One infected swan found in Scotland last week remains the only confirmed case of H5N1, despite more than 1,100 birds being examined since the end of February.

A spokesman for the SVS in Worcester said it would receive the test results on the latest batch of birds within a week.

He said the service had been inundated with calls since the swan was discovered in Cellardyke, Fife.

Since mid-February, it has responded to 242 calls from the public.

The Government's top scientific adviser Sir David King said bird flu was "absolutely not" present among poultry in Britain, adding that he was "fairly optimistic" about its absence from the wild bird population.

Experts at the Central Science Laboratory in York are continuing DNA tests on the infected dead swan, which was found washed up in the harbour of the coastal town, in an effort to determine its exact species.

The bird was found in an advanced state of decay, with its head missing, making it hard to identify.

Finding out which species the bird was will help epidemiologists know if it was migratory and where it might have come from.

Rural Affairs Minister Ross Finnie said experts thought it was likely that the bird, found at Cellardyke harbour in Fife, was native.