The white nutria, which is considered one of the most ecologically harmful invasive species on the planet, was captured on video chomping on rushes at the reservoir, known for its rich diversity of plant life.

Other images posted on social media show the animal, which is also known as a rat beaver and can carry rabies as well as other dangerous diseases, swimming in the reservoir waters.

Imported into Poland from America in the 1960s, Nutrias became a popular farm animal in Poland where they were bred for their fur and meat.

Although Nutria farm breeding has almost completely disappeared from Poland, it is thought that the latest sighting could have been of one that escaped.

Despite being hailed as a local attraction after becoming an internet hit, local news portal Nowa Trybuna Opolska warned: “Its presence shouldn't make you happy.

“It is an invasive species that may threaten native fauna.”