Patricia Reckel was walking in the Pétrusse valley on Wednesday morning 9 August when she came face to face with the creature, which she was unable to identify.

“I had never seen such an animal before and I was born and grew up near the Pétrusse valley,” she told Delano.

Reckel took some photos of the animal on her phone and later posted them on social media.

The sighting was in the valley beside boulevard de la Pétrusse.

Delano contacted conservation association natur&emwelt which identified the creature as a myocastor-coypus or nutria.

According to the biological invasions tracking website neobiota.lu, the species was first documented in Luxembourg in 1957 at the Alzette river next to Hunsdorf. The entry reads:

“Currently, it is only observed sporadically in Luxembourg. Because of its occurrence in the bordering regions of France (Chiers, Moselle) and Germany (Saar), it is likely that the species will populate national watercourses within the near future (Naturverwaltung 2013).”

“Overgrazing by coypus can cause local extinctions of aquatic plants, the destruction of reedbeds and of fish nursery areas. Due to its burrowing activity, the species degrades river banks and affects river flow. Rare marshbirds are affected by nest destruction, egg predation or habitat destruction. The coypu could also act as a reservoir of different pathologies and causes damages to agriculture. Coypus are included in the appendix to the recommendation no 77 of the Council of Europe as a species which has proved to be a threat to biological diversity and for which eradication is strongly recommended.”

“Whatever type of animal it was, it stood still and looked at me with an amazingly cute look," Reckel said.

An earlier version of this article incorrectly identified the animal as a muskrat. This was because of an incorrect link to the neobiota.lu website received from natur&emwelt.