Meanwhile, all but one of the passengers on the Christchurch to Auckland charter flight have been tested.
A man who flew to Auckland from Christchurch on the charter flight on September 11 tested positive five days later. He had previously had two negative tests.
There were 86 people on the flight.
Of those tested, all results are negative including the one pending test result from yesterday which returned negative today.
The remaining passenger is a young child. A risk assessment, including the child's parent testing negative, has determined the child is considered low risk and no test is currently required.
There are 22 people isolating in the Auckland quarantine facility from the community, including 10 people who have tested positive for Covid-19 and their household contacts.
Only one person remains in hospital. They are on a general ward at Middlemore.
Update on the three cases reported on September 23
Public health services continue to contact trace, test and isolate close contacts of the three community cases reported this week.
As previously reported, the three people are part of the same family group - two had been in managed isolation in Christchurch and returned home on the charter flight, while the third is a household contact.
There are now a total of 44 close contacts associated with these cases - 36 have returned negative test results and the remaining have been or are in the process of being tested. All are now self-isolating. The only close contacts still with results pending are in Auckland.
There were two new cases of Covid-19 yesterday - one in managed isolation and one historical, detected during contact tracing.
Of yesterday's cases, the imported case was a man in his 30s who arrived in New Zealand from Russia via the United Arab Emirates and tested positive on his third day in isolation.
The historical case was a passenger on a charter plane from Christchurch to Auckland. Three other people on that flight had already tested positive.
The person had returned negative tests at day three and day 12 of their managed isolation, the ministry said.
"From additional testing and serology analysis, we have determined there is no link to the Christchurch returnee group," the Ministry of Health said in a statement.
"Any infection would have occurred overseas prior to the person returning to New Zealand earlier this month and they are no longer infectious."
"As we have previously said about historical cases, we know that some people can return a positive PCR test long after they have recovered from the illness and are no longer infectious."
All 86 passengers on the flight had now been tested, except one, a young child. All had been negative apart from the three previously reported cases and the one case confirmed today.
That testing regime was started after a man in his 40s and flew home to Auckland on a chartered flight. He had returned to New Zealand from India on September 11 and spent 14 days in managed isolation in Christchurch.