The parent of a student at Southland Boys' High School has tested positive for the COVID-19 coronavirus.
One of the eight new cases of coronavirus announced on Wednesday, the man arrived back from the Gold Coast on March 5.
Southland District Health Board (SDHB) says the entire family is now in self-isolation.
"We are undertaking contact tracing for the parent and will be asking any close contacts to self-isolate for 14 days from when they were in close contact," it said in a statement to parents.
"The student is completely well and has no symptoms. He is now staying home as a precaution, in case he develops the disease in the future, and the whole family is now in self-isolation."
As of Wednesday, there are now 20 confirmed cases of COVID-19 in New Zealand - one of them a student from Dunedin's Logan Park High School.
As a result, 150 close contacts of the Dunedin student have been put in self-isolation.
They will all be tested within the next 20 hours and the school will now remain closed until after the weekend.
However the SDHB says there is little risk to people at Southland Boys' High School.
"Please be reassured there is minimal risk to students, staff or others at the school," it said in its statement.
"Please understand that people are not considered at risk if they have been close to someone considered a close contact - as the close contact does not have the disease.
"Contacts of close contacts do not have to take any action such as isolating themselves."
It also issued a warning in light of the severe social media abuse some victims of the disease have been confronted with.
"Please ask your son/sons not to post any information on social media as this could lead to bullying. Netsafe provides guidance on online behaviour."