Polish scientists have identified the first cases of coronavirus in mink at a farm in the north of the country.
The Medical University of Gdansk said on Tuesday that eight animals were found to be infected at a breeding farm in the Pomeranian Voivodeship.
Scientists had examined throat swabs from 91 farmed mink in total for the presence of coronaviruses.
Poland, a major producer of mink fur, started coronavirus tests among its farmed mink and workers this month after a mutation of the virus was found in Denmark.
The Danish government announced a nationwide cull of more than 15 million mink but later withdrew the order because it had no legal basis for those not contaminated by the virus.
Hundreds of Danish farmers and mink breeders drove past the government's offices in Copenhagen to demonstrate against the measure.
Veterinary and sanitary authorities in Poland said last week that 18 coronavirus cases had been identified among mink farmworkers since the start of the pandemic, but it was unlikely that to have been spread by the animals.
"This is the first case of confirmed infection of farm animals with the SARS-CoV-2 virus in Poland," the Medical University of Gdansk said in a statement.
"The obtained results indicate the possibility of transmission of the virus from humans to minks."
"In-depth genetic research is currently underway to determine the probable origin of the virus and to enable comparison with known SARS-CoV-2 genetic sequences."
Scientists say the test swabs were subjected to a similar two-gene test used in human diagnostics.
Various research centres across Europe have been studying for infections of COVID-19 in many animal species, including minks, rabbits, bats and rodents.
As in Denmark, industry groups are likely to object to the test results, over fears Poland could introduce a nationwide cull.
Poland is the world’s third-largest fur producer after China and Denmark, according to animal rights groups that are campaigning for an end to breeding animals like mink for fur.