Romanian officials are awaiting the results of a second test by British scientists to see if a second outbreak of bird flu in the country is the H5N1 strain.
The strain is potentially lethal to humans with Liam Donaldson warning that should the disease arrive in the UK it could result in about 50,000 deaths.
Speaking on the BBC’s Sunday AM programme Sir Liam acknowledged that a flu pandemic was inevitable, but it was “less likely” that an outbreak would occur this winter.
The government’s Central Science Laboratory lab is testing samples taken from swans which died in ponds near the village of Maliuc in the Danube Delta.
Romanian authorities have been culling thousands of birds, and the affected area has been placed under quarantine.
The H5N1 bird flu strain found in Romania has been linked to more than sixty human deaths in Asia.
Maliuc is only 30km (20 miles) from Ceamurlia de Jos, where the country’s first confirmed case of the virus was found.
In preparation for a potential outbreak a delegation of British scientists has travelled to south east Asia to see how a outbreak of bird flu could be tackled.
Experts from the Medical Research Centre will travel to the region where the disease has claimed 60 lives, mainly poultry farmers who contracted the disease after handling infected stock.