Two Covid-positive crew members who were onboard a container ship in Bluff have returned to the vessel having briefly been taken to hospital.
It comes as a further six new cases onboard the Mattina container ship, currently in quarantine in Bluff, have now tested positive for Covid-19.
Today's new virus cases bring the total to nine. There are 21 crew members on the vessel.
Two of today's new cases were transferred to Southland Hospital's emergency department this morning because of their symptoms, Ashley Bloomfield said at this afternoon's Covid-19 media conference.
"Of course that is being undertaken using strict infection prevention and control protocols," he said.
Southland Hospital's acting general manager Jo McLeod says the two crew members have now returned to the ship.
"The two mariners have been assessed and did not require admission."
Authorities are continuing to assess whether the crew will remain onboard the ship through their quarantine period.
Regular testing of the crew is ongoing.
"We know from fishing boats that we have in port in Lyttelton and Wellington at the moment that we do see additional infections just because of the nature of the vessels and so it may well be that there are further positive cases," Bloomfield said.
Further test results are expected in the coming days.
Genome sequencing on the cases is also under way to determine where the original infection came from.