The bird, which was imported from South America and arrived in this country in mid-September, was found to contain the H5 strain of the virus after scientists carried out tests following its death a couple of days ago.

It is the first time a case of avian flu has been confirmed in Britain since 1992 but Defra were unable to confirm if it is the lethal strain H5N1, which has killed 60 people in south-east Asia.

The chief veterinary officer, Debby Reynolds, said last night: "We do know it is a highly pathogenic form, but we don't have the formal, official confirmation of the N-type. I don't intend to speculate on the N-type until I have formal, official confirmation of this."

The bird was part of a mixed consignment of 148 parrots and "soft bills" which arrived on 16 Sept-ember from Surinam and were being held in a biosecure quarantine unit with a consignment of around 200 birds from Taiwan. The birds - around 300 in total - have now all been humanely culled and all those which came in contact with the culled consignment have been given antiviral treatment, Defra said.

Asked about the incidence of avian flu in Surinam, she added: "I am not aware of any official reports, but that is something we need to absolutely check."

The confirmed case did not affect the UK's official disease-free status because the disease was identified in imported birds during quarantine, according to Ms Reynolds, and this was later confirmed by European Union officials. Ms Reynolds said this incident "showed the importance of the UK's quarantine system".

Professor Hugh Pennington, of Aberdeen University's department of medical microbiology, said tests would have to be carried out on the dead parrot to establish whether it died from the strain of H5N1 which has killed birds across the Far East and Europe.

He said that, as well as different, less dangerous strains of the virus, it was possible the bird died of another H5-type virus, as it had come from South America where the Far East avian flu has not been found.

Avian flu has been found in Romania, Turkey and Greece in recent weeks after apparently being carried by wild birds from Asia. Last night it was also confirmed in Croatia.

Earlier today the EU ordered restrictions on bird markets and shows and urged nations to present a programme of vaccination for zoo birds as part of increased measures to avert the spread of bird flu.

The European Commission announced it was considering setting aside a €1bn (£677m) "solidarity fund" to be used in the event of a pandemic. Money would be used for anti-viral drugs and vaccines to help combat a potentially deadly outbreak.

Earlier this week Patricia Hewitt, the Health Secretary, said the UK had already ordered a large quantity of the anti-viral drug Tamiflu to treat flu victims, as well as a smaller quantity of vaccine against the current strain of bird flu.

She also said the risk of a pandemic remains unchanged, according to the World Health Organisation. "There is no evidence of avian flu being transmitted from one person to another - human-to-human transmission, that is what would be required for a pandemic," she said.

Avian flu is a highly infectious viral disease which affects birds and varies in severity, from causing no deaths to killing entire flocks within hours. Warning signs include breathing problems, swollen heads and a drop in egg production. It is most easily spread through bird secretions, particularly faeces, but can also be passed via contaminated objects.

The deadliest strain of the virus is H5N1. It is also highly contagious and so has sparked global concern. It kills almost all infected fowl, many within 24 hours. The strain has leapt the species barrier, killing 60 people working with stricken birds in south-east Asia. The fear is H5N1 will mutate so it becomes more easily transferable from human to human.

A virus in many forms

* There are many strains of Avian Influenza (AI) which vary in their ability to cause disease.

* The different types of AI viruses are categorised according to their ability to cause severe disease (pathogenicity) as either highly pathogenic avian influenza (HPAI) viruses or low pathogenic (LPAI).

* One of the most dangerous is the strain that is identified as H5N1.

* The most contagious strains are H5 and H7 and both of those are usually fatal to birds.

* The H5 part of the strain can be identified more easily than the N-number.

* It has been established that the dead parrot has the H5 strain but the N-number, which may determine whether it will kill humans, is unknown. Further tests are required to answer this question

* Testing for suspected cases in Europe is carried out by scientists at a specialist laboratory in Weybridge, Surrey.