The authorities in the Czech Republic have confirmed their first case of the H5N1 bird flu virus.
Tests are being carried out on a number of dead birds
Preliminary tests on a dead swan found last week 130km (80 miles) south of Prague show the bird had the strain, which can be lethal to humans.
Further tests are being carried out at the EU reference laboratory in the UK.
The European Commission has proposed additional aid to farmers in member states hit by a drop in egg and poultry consumption due to bird flu outbreaks.
Thirteen EU countries have now confirmed outbreaks of bird flu, which has killed more than 100 people in Asia since 2003.
"A definitive confirmation of the highly-pathogenic type... can be expected from the EU reference laboratory in Weybridge in Great Britain in the middle of next week," the Czech agriculture ministry said in a statement.
Spokesman Tomas Loskot said another dead swan had tested positive for the H5 virus and would be tested for the H5N1 strain.
The Czech authorities have implemented safety measures in accordance with EU rules - including a protection area around the site on the Vltava river where the swan was found.
The European Commission has put forward proposals to help those affected by the crisis.
It says that consumption of poultry and eggs has fallen dramatically in some member states, leading to a sharp reduction in prices.
Current rules only allow the EU to offer compensation to farms directly hit by bird flu or to those prevented from moving stock because of restrictions. The regulations do not take into account problems of falling sales due to lack in consumer confidence.
But the commission says the EU should now help to fund half the cost of programmes undertaken by member states to restore confidence in the sector.
"This unprecedented situation can no longer be dealt with using the existing tools," said EU Agriculture Commissioner Mariann Fischer Boel.
"Each member state will then be able to design the measures best suited to its particular situation."
The proposal will be sent to the European Parliament and the EU Council of Ministers for adoption by the end of April.
The H5N1 virus can be caught by humans who handle infected birds, but it is not yet known to have passed from one person to another.
However, experts fear the virus could mutate to gain this ability and in its new form trigger a flu pandemic that could kill millions.