Bay of Plenty Regional Council asks people to report wallaby sightings as soon as possible so the pest animals can be contained before they become established in new areas.
The reminder comes after reports of wallaby sightings in Ohiwa, Opotiki, Whakatane and Papamoa.
The council responded to these reports by deploying a contractor with a trained wallaby-indicating dog.
Two of the sightings were recent and were successfully dealt with but, where the information was not immediately reported, the sightings were not recent and no wallaby sign was found.
Council biosecurity manager Greg Corbett said it was important for people to report wallaby sightings to us as soon as possible.
"Our chance of dealing with these animals is much greater if we can get a dog on site before the scent trail goes cold."
Given the distance these wallabies were from their known distribution points, it wa likely people were moving them around and releasing them, Greg says.
"This is potentially very damaging to the environment. Should wallabies become established in Te Urewera, for example, it would have severe consequences."
Wallabies were listed as a containment pest in the Bay of Plenty Regional Pest Management Plan and were unwanted organisms in the Biosecurity Act, which means it is an offence to move or release them.
The animals cause significant damage to native bush by feeding on native seedlings, ferns and grasses.
They could also cause problems for forestry and farming by feeding on pine and eucalyptus seedlings and competing with stock for pasture.
Once established in native bush, wallabies feed on seedlings, altering the species composition and ultimately depriving native birds and animals of food and shelter.
The council was also concerned hunters may be shooting female wallabies and taking the joeys home as pets.
"This is an offence," Mr Corbett said.
"People keeping wallabies as pets may also contribute to their spread as the animals have a nervous temperament and a strong drive to escape from captivity."
The regional council controls wallabies in partnership with the Department of Conservation and Waikato Regional Council.
Wallaby sightings can be reported by calling 0800 STOP PESTS.
Wallabies are grey/brown in colour, with adult animals having a paler grey underbelly. Females weigh up to 5.5kg and males up to 7kg.