In a statement this afternoon, the authority said a contractor identified possible wallaby scat this week and a detector dog found the potential presence of an animal in the area.
However, a wallaby has not been confirmed by professional sighting.
Biosecurity and biodiversity operations manager Ali Meade said wallabies are exclusion pests in Southland, meaning there are no established populations, and the authority wants to keep it that way.
“We urge locals not to go out looking for the potential pest and to let specialists trained in controlling these animals do their work.
"Public interference risks the success of the operation and increases health and safety issues during the work. It also puts our efforts to maintain wallabies as an exclusion pest at risk,” she said.
Wallabies are considered a pest as they can cause significant economic and environmental impacts as they eat grass, native shrubs and trees. They can damage pasture and fences, add to erosion issues and damage young tree seedlings.
Ms Meade said the investigation into this week's possible sighting was still being planned, and the public would be updated.
"We know the community are proactive about reporting pests and we appreciate their commitment to protecting Fiordland. They can help us to do that by reporting any sightings.”
This year, there have been two reports of wallabies near Te Anau, including this week, and three reports on the Te Anau-Mossburn Highway (State Highway 94) since 2022.
All reports have been made by members of the public, however no wallabies were found.
There have been 19 total reports in Southland since 2015. All reports have been investigated by biosecurity officers, and one live wallaby was found in Invercargill in 2016.
• The public should report all sightings of wallabies at www.reportwallabies.nz