Two weak positive Covid-19 results have been detected in Wellington's wastewater, the Ministry of Health has announced.
It said ESR had reported a weak positive test result late on Friday. A follow-up sample yesterday returned a second weak positive result.
The ministry said it was "most likely" the two weak positive results were due to recently-recovered cases continuing to shed the virus.
Three recovered cases who live in the Wellington region had left Auckland's quarantine facility, Jet Park, in recent weeks, the ministry said.
It also said a further historical case left a Wellington MIQ facility the same day the second sample was taken.
"Additionally, it is possible that one or more recently recovered cases from elsewhere could have flown into Wellington."
Wellington City Council said the weak positive sample had been detected at its Moa Point Treatment plant, which serves the residential population of the capital.
Further wastewater samples in Wellington were being tested.
ESR consider a single recovered person shedding the virus may be detected in wastewater.
It conducts regular wastewater testing across sites in Auckland, Wellington, Christchurch, Rotorua, Hamilton and Queenstown as an additional surveillance tool in the fight against Covid-19.
However, the ministry said it encouraged anyone with coronavirus symptoms, particularly in the Wellington region, to get tested promptly.