The head of the Friedrich-Loeffler-Institute, Thomas Mettenleiter, issued a fresh report with recommendations for Germany's veterinary workers, citing the presence of the H5N1 in a dead domestic goose examined at Vickersdorf, Thuringen.
Earlier, scores of wild birds killed by the virus had been found in the area.
France's Agriculture Ministry said Thursday that three wild swans found in the Moselle department had also died of H5N1.
The reports come in the wake of a season of bird flu scares in Europe, with poultry farms in Hungary, Britain and the Czech Republic, and most recently of Germany's Bavaria and Saxonia last month, affected this year.
In France, bird flu was registered last February in the Ain department in the east of the country. The authorities reacted promptly and contained the virus by culling or vaccinating all poultry on 11,000 farms.
