Mink are known to regularly escape fur farms and the risk that infected mink are now in the wild was confirmed on Thursday.

“Every year, a few thousand mink escape. We know that because they are an invasive species and every year hunters and trappers kill a few thousand wild mink. The population of escaped mink is quite stable,” said Sten Mortensen, veterinary research manager at the Danish Veterinary and Food Administration.

This year, Mortensen said, there was a risk that about 5% of the minks that escaped from farms were infected with Covid-19.

The risk of the escapees infecting other animals was low, he said, because mink were “very solitary creatures”. But, if they did, the animals most likely to catch the virus would include wild animals such as ferrets and raccoon dogs and “susceptible domestic animals” such as cats.