There is one new case of Covid-19 in the community in Christchurch, the Ministry of Health says.
It ends 10 straight days of no community cases of the virus in New Zealand. The Ministry announced the new case shortly after 8pm today.
The case is a staff member working in the Christchurch managed isolation facility where a group of international mariners have been staying. A total of 31 positive Covid cases are now linked to a group.
They are among 440 fishers from Russia and the Ukraine, 270 of whom are due to go out on three Independent Fisheries boats next month.
The new case was tested as part of routine testing for staff at the Sudima at Christchurch Airport. They returned a negative test on Thursday, October 29.
On Saturday however, they developed symptoms and sought a further test on Sunday, returning a positive result which was received today.
"The person is now in isolation at home and reports taking care to isolate themselves as soon as they developed symptoms," the ministry says.
The first of the international mariners were due to have completed their managed isolation tomorrow morning but will have it extended for at least 24 hours as an additional precautionary measure.
The ministry said full details of the case, and the actions taken in response would be provided in a 1pm press conference tomorrow.
Precautionary measures for the international mariners include additional tests - up to four for some individuals and an already lengthened stay in managed isolation.
This is the third time Covid-19 has re-emerged in the community,
New Zealand went 102 days without a case until August when an Auckland cluster forced the city into a two-week level-3 lockdown.
Then in October, after 22 days without a new case in the community, a marine engineer tested positive after carrying out work on a ship in Auckland, the Sofrana Surville.
Four cases of Covid-19 were reported in managed isolation this afternoon. One of those an international mariner staying at the Sudima in Christchurch, detected at day 15 testing as a close contact of a day 6 case.
The other three people were a person at an Auckland quarantine facility, who arrived on October 19 from Milan via Singapore and tested positive to routine testing at around day 12.
Another person arrived from London via Singapore on October 28 and tested positive to routine testing at around day 3. They are now in the Auckland quarantine facility.
And the forth case was detected in managed isolation in Auckland, after being given permission to join a family member recently arrived from overseas. The family member has previously been recorded in our positive case totals. Today's case will be recorded as an import-related case.
Last month Air Commodore Darryn Webb told Newstalk ZB staff at the Sudima Hotel took infection prevention measures including physical distancing, regular and thorough cleaning, PPE use, basic hygiene practices and daily health checks, Webb said.
He expected the number of positive cases within the fishermen group to increase.
"I think it's logical to expect that. We knew in the planning that places like Russia are high risk."
Webb said the processes in place around testing at the boarder were robust.
"We have an exclusive use facility for these fishermen. Part of the process early on is that we do know they are coming from a high risk area so let's provide them a single location."
He said there was a 24-hour delay as the aircraft worked through its process in Moscow and the fishermen were assembled there for 48 hours and then en route for 18 hours.
That period of time provided an opportunity for the virus to spread.
In August, a Rydges Hotel maintenance worker contracted Covid-19 from a guest in the managed isolation facility.
His strain matched that of a guest who flew in from the United States before testing positive for Covid-19 and then being transferred a quarantine facility.
Director general of health Dr Ashley Bloomfield later said investigations had revealed the worker used a lift "very shortly" after the woman.