The Government is being warned it may have to stop New Zealanders returning home from countries with a high risk of Covid-19 like India.
Modeller and economist Rodney Jones says so far this country has done an extraordinary job of fighting the pandemic, but the risk of infections getting through the border is growing.
There has been a surge of cases from India this month.
The group cluster of six cases and 31 contacts is linked back to a man who flew in from India on 27 August and who was diagnosed with the disease after he left managed isolation.
The source of his infection is still being investigated, but the genome sequencing is consistent with two confirmed cases from the same flight.
Economist Rodney Jones, who has been modelling Covid-19 cases told RNZ reporter Charlotte Cook there needs to be a focus on the threat from overseas.