The four household contacts for the person who was reported as testing positive for Covid in Tonga yesterday have now all returned negative tests.
The contacts, two in Wellington and two in Christchurch, are all self-isolating and will have day 5 tests.
The pair isolating in Wellington flew to the city from Christchurch a day before a person they live with flew to Tonga and tested positive for Covid-19.
Health officials are now urging residents in the capital city to get tested if they are unwell and get vaccinated immediately amid fears the outbreak has reached across Cook Strait and into the lower North Island.
It comes as 160 new community cases were recorded today across New Zealand - a record number of daily infections in the current outbreak.
The Covid-positive person who arrived in Tonga on Wednesday now connects three main centres - Wellington, Christchurch and the small Pacific Island nation.
Health officials said they returned a negative pre-departure test before leaving New Zealand and were fully vaccinated with the Pfizer BioNTech vaccine and asked anyone in Wellington or Christchurch with even mild symptoms to get tested immediately.
"Anyone with symptoms is asked to please get tested and reminded to get vaccinated today if they have not already", the ministry said in a statement today.
"The Ministry, along with the Ministry of Foreign Affairs and Trade, continues to work with officials in Tonga to confirm the case."
The Tongan case is believed to be linked to the two cases of Covid-19 reported in Christchurch on Thursday. Both of those people lived together in the suburb of Bishopdale.
One of the people had permission to go to Auckland to provide childcare and tested negative before returning to Christchurch.
The second is a truck driver who completed deliveries around the Christchurch area and some trips to North Canterbury.
Both people became unwell last week and were tested two days ago, but returned positive Covid tests on Wednesday night.
Officials revealed today that a new case in Christchurch is an individual who had recently returned to New Zealand.
They'd had multiple negative tests in MIQ in Auckland including a day 12 test, before being released and travelling to Christchurch.
Kaniva News reported that the case in Tonga was confirmed by Tonga Ministry of Meteorology, Energy, Information, Disaster Management, Environment, Climate Change and Communications chief executive Paula Ma'u.
Ma'u said Tongan authorities had received the report of the Christchurch Covid-19 cases after the passengers arrived in Tonga.
"The passengers were being processed according to the normal procedure at the quarantine facilities and tested for Covid-19."
The repatriated flight arrived with passengers including seasonal workers as well as some of Tonga's Olympic team officials who got stuck in New Zealand after the Olympic Games.