People in Upper Hutt around Featherston are urged to look out for wallabies, after sightings of the dama variety in the region has authorities concerned.
Dama wallabies are capable of causing significant environmental damage, and several corpses have been recently located in the Pakuratahi Forest and near Kaitoke Regional Park.
Greater Wellington Biosecurity manager Davor Bejakovich asked the public to report any sightings of wallabies.
"We will follow up all reported sighting as it is critical to ensure wallabies do not establish themselves in our region," he said.
The appeal for public sightings follows the discovery of faeces during extensive searches in the area, including installation of trail cameras for surveillance and taking DNA samples from water.
Dama wallabies are kangaroo-like marsupials, grey to reddish brown in colour that stand around 0.5m tall with tails as long as half their height.
Most dama wallabies are found in the wider Rotorua Lakes area, and the larger Bennett's wallaby in South Canterbury - but both species are spreading into the Greater Wellington Region.
Damaging effects caused by wallabies can include preventing the regeneration of native bush, depleting forest understory and possibly even affecting water quality.
They can also reduce tall tussock grassland vegetation to bare ground, which increases the risk of soil erosion.
Bejakovich said they had so far not found any more of the marsupials.
"But we're hoping local landowners, residents and park users will keep the area under surveillance so that we can be sure wallabies haven't settled in the area.
"Not everyone is aware that wallaby populations exist in the wild in New Zealand so we're distributing signs and other material throughout the area to build awareness and encourage people to report sightings.
"We need to keep them out of this region and the community can be assured that we will do what's necessary to protect our environment against their establishment.
"This is an opportunity for people to help protect our environment by reporting any signs or sightings of wallabies."
Anyone who sees what they believe is a wallaby should report it to www.reportwallabies.nz.