Officials are still working on which Covid-19 variant the Sydney traveller has, after they visited Wellington over the weekend while infectious with coronavirus.
Dr Ashley Bloomfield said genome sequencing was still underway, however the case was epidemiologically linked to Sydney's Bondi cluster.
The variant was expected to be established later today.
Covid-19 Response Minister Chris Hipkins said the results had not yet been supplied by Australia, but he was confident it would be shared with New Zealand "as soon as they get them".
He said NSW's sharing of information was "fast and efficient".
There would be a meeting at 2.30pm with Australian health officials in which Dr Bloomfield expected test results may be shared.
This morning, Hipkins told Breakfast "the advice we got yesterday was that we should work on the basis that it would be the Delta variant and linked to the current cluster" in Sydney.
Professor Michael Baker told 1 NEWS last night if the traveller was confirmed to have the highly-infectious Delta variant, "on the face of it, this could be the worst-case scenario".
"They spent the whole weekend in indoor venues and literally have contact with thousands of people.
"This can cause huge amounts of transmission of the virus.
"That’s a big threat," he said.
New research has indicated two doses of the Pfizer or AstraZeneca vaccines can be highly effective against serious illness from the Delta strain of Covid-19.
The traveller had had one dose of AstraZeneca.
Results have varied, however British epidemiologist Neil Ferguson believed the Delta variant to be 60 per cent more transmissible than the Alpha variant discovered in the UK.
New South Wales Professor Mary-Louise McLaws told RNZ it could be up to 90 per cent more infectious than other strains.