Two crew members onboard the Mattina container ship currently in quarantine in Bluff have tested positive for Covid-19.
In a statement, the Ministry of Health (MOH) said the Marshall Island-flagged vessel came into the port last night and all 21 crew members were tested this morning.
"Rapid tests were ordered for the two symptomatic cases. Health officials report their condition is regarded as improving. The test results for the remainder of the crew are due back later tonight," the statement said.
"Both crew members who've tested positive, joined the ship in Singapore on 2 July after providing negative pre-departure tests.
"Health officials in Southern DHB are working with other agencies to determine the next steps for the ship. In the meantime, the crew members remain on board the Mattina."
The Mattina is currently in quarantine in a secure area of Bluff's port.
The area is inaccessible to members of the public and fencing will be put up to further restrict access to the ship.
However, South Port confirmed a maritime pilot who helped to navigate ships into the port had boarded the ship earlier.
South Port said it was alerted on 16 July by Public Health South that two crew members aboard the ship were showing flu-like symptoms and had been isolated from the rest of the crew.
"A South Port pilot who has been fully vaccinated against Covid-19, boarded the vessel and piloted it into the port. Strict protocols were followed to ensure the risk to the pilot was minimised."
That included using personal protective equipment and physical distancing.