Three more crew on the Mattina container ship quarantined at Bluff have tested positive for Covid-19.
There are also three new Covid cases to report today in managed isolation, the Ministry of Health says.
The trio of new Mattina cases was reported at 9am today.
"One further result is currently under investigation due to a high CT value; and three more have serological evidence of past infection and therefore are not deemed infectious at this stage," the ministry said in today's update.
"Two further positive results aboard the Mattina were reported after 9am and will be officially added to our case tally in tomorrow's update. We are reporting these out of cycle because of the high public interest in the Mattina.
"The three remaining crew have returned negative tests."
All of the Mattina crew who have tested positive will remain quarantined on board, the ministry said.
"If those who tested negative return another negative test today, they will be transported to a Christchurch-based quarantine facility using a well-planned securely managed transport plan, including the use of Infection Prevention and Control (IPC) protocols.
"It is safer to manage the smaller group of negative cases, by taking them off the ship."
The number of active Covid cases in New Zealand is 62.
Today's three new cases in managed isolation are travellers from Fiji and Ghana.
There was also a fourth case reported today, which is historical.
It was a good day on the Covid-front yesterday, as the Ministry of Health reported no new cases in managed isolation facilities or in the community.
Six mariners on board the Mattina container ship, in quarantine at South Port in Bluff, are now officially on New Zealand's national Covid-19 tally, however.
The six crew members, as well as three more reported on Tuesday, take the total number of Mattina mariners affected by the virus to nine out of 21 staff.
A crew member previously reported to have Covid-19 has now recovered, the ministry confirmed.
The number of active cases in New Zealand was 56 as of yesterday's statement. Since the beginning of the year, there have been 99 historical Covid cases - out of a total of 655 cases.
The seven-day rolling average of new cases detected at New Zealand's border stands at five. While our total number of confirmed cases is 2472.
Health authorities said two of Mattina's infected crew were taken from the ship to Southland Hospital's emergency department yesterday. They have since returned to their ship.
"Officials, including public health, are today assessing whether the rest of the crew will remain aboard the ship throughout their quarantine period," yesterday's statement said.
Additional testing carried out on the crew yesterday is due to be reported on publicly today.
The Southern District Health Board has already got plans in place for the management and treatment of any other crew who may return a positive result.
The Ministry of Health also said it was expecting further information about the infection source when the genome sequencing is completed in the coming days.
Quarantine free travel with New South Wales remains paused, and so far 38 people in New Zealand have been identified as people who have been in locations of interest in Victoria and Queensland.