This is the fourth case of avian flu registered by Polish veterinary authorities since last week when the deadly virus was discovered at three turkey farms in the country.
Ewa Lech said the Polish veterinary authorities had set a safety zone around the site to prevent the spread of the virus.
Russia imposed on Thursday temporary restrictions on the import of poultry, eggs and all poultry products from Poland following an outbreak of bird flu in the country.
Russia's agricultural watchdog Rosselkhoznadzor said the restrictions also applied to bird feed and feed additives, as well as used bird-farming equipment.
Poland is still subject to a two-year Russian embargo on its meat products, imposed over allegations Poland was supplying poor-quality meat from third countries. In retaliation, Poland has vetoed talks on a new Russia-EU partnership and cooperation agreement.
