There are now six Omicron community cases after the highly contagious variant slipped into the air network,infecting two Auckland Airport workers, an MIQ staffer and two close contacts.
Another Omicron-positive person spent two days moving about in Palmerston North while potentially infectious after being discharged from a managed isolation facility.
University of Canterbury professor Michael Plank said if the cases have Omicron, it will likely trigger an outbreak.
"Obviously that is a significant number of cases and significant level of exposure on five flights, and with no clear link to the border that I'm aware," Plank said.
"That would suggest there is likely to be a lot more cases out there that haven't been found.
"But that's a big if at the moment, and we won't know until the sequencing is complete."
It comes as hundreds of Omicron cases have been picked up at the border in recent weeks.
The wave of border cases and recent instances of Omicron slipping into the community has led Plank and other experts to warn it is likely just weeks or even days before a wider outbreak is seen.
That could lead to Auckland having up to 1800 cases a day within weeks of community transmission occurring, they say.
Prime Minister Jacinda Ardern has also urged Kiwis to prepare, saying it's a matter of when, not if an outbreak occurs.
She said all of New Zealand would move to the red traffic light setting within 24 to 48 hours of Omicron community transmission.
"So far we've managed to keep the leaked border cases contained thanks to those people getting tested early and our contact tracing system working well, but sooner or later our luck is going to run out," Plank said.
Another Auckland Airport worker has been confirmed as having Omicron as the race is on to get booster shots in Kiwi arms. Photo / NZME
"This is happening regularly enough that you wouldn't be surprised if something slips through the net in the next few weeks or even sooner."
Prominent University of Auckland microbiologist Dr Siouxsie Wiles worried that the Government's red traffic light system would do little to contain an Omicron outbreak.
Under red conditions, public facilities and retail can operate with capacity limits, and restaurants and cafes can serve up to 100 people if using vaccine passes.
But Wiles said indoor dining, night clubs and similar activities would be high risk in an Omicron outbreak and said certain activities and venues should be shut down.
"If we can stop people spreading the virus, then we can stop Omicron. And the more we do to stop transmission, the quicker it will be over."
It comes as the nine Covid positive Motueka cases reported yesterday were found to have all been from the same household.
They have been linked to an Air NZ flight and crew member who also tested positive to the virus.
Air NZ chief medical officer Dr Ben Johnston said the worker was fully vaccinated and found to be positive as part of routine testing.
"Close contacts including any other members of our aircrew are being advised and will be tested and isolated according to the Ministry of Health requirements."
He was confident staff were following Covid precautions and protocols "diligently".
The Ministry of Health said the crew member worked on five flights while potentially infectious and these have been named locations of interest. The flights are:
• Flight NZ 5083 from Auckland to Nelson at 5.20pm on January 16. • Flight NZ 5080 from Nelson to Auckland at 4pm on January 19. • Flight NZ 5077 from Auckland to Nelson at 2pm on January 19. • Flight NZ 5049 from Auckland to New Plymouth at 7.50pm on January 19. • Flight NZ 5042 from New Plymouth to Auckland at 1.50pm on January 20.
The ministry yesterday also confirmed a second Auckland Airport worker had the Omicron variant.
The worker has potential links to Covid positive travellers in managed isolation in Rotorua and Auckland.
People queue for vaccinations and booster shots at the Nelson centre on Paru Paru Rd after nine new cases were found in nearby Motueka. Photo / NZME
Thirty-two contacts have been identified with one household member testing positive and 16 others returning a negative result.
