Travellers from countries where COVID-19 is rampant should go into quarantine for a week before they fly to New Zealand, a leading epidemiologist says.
Twelve people in managed isolation tested positive for COVID-19 on Thursday - 10 were on the same flight from India.
The announcement prompted calls for tougher restrictions for arrivals from countries considered high-risk.
The Ministry of Health is considering whether pre-departure testing for people flying to New Zealand should be part of the country's border protection.
Otago University epidemiologist Michael Baker told Morning Report the pre-flight test is one of two moves he supports. The other is that anyone travelling to New Zealand from a list of countries with large COVID-19 outbreaks should go into quarantine for a week beforehand.
If their pre-flight test was positive, they would need to delay their departure to New Zealand by a month while they cleared the virus.
It would be an alternative to closing the borders to certain countries, Baker said. All travellers would still undergo the two weeks in isolation and two COVID-19 tests on their arrival.
"The goal here is not to stop every case, it's to reduce the number arriving in New Zealand which puts a strain on our system.
"This is all about probability, it's about decreasing the risk of anyone getting through this managed isolation system in New Zealand."
The list of countries would need to be carefully targeted and would not be permanent, he said.
While New Zealand was now operating a sound border and isolation system, it was not perfect, and might need to be fine-tuned from time to time to reduce the risk of positive cases getting into the community.
As many as 5 to 10 percent of people have a longer incubation period than 14 days for the virus, Prof Baker said.