The Auckland household contacts of the traveller who recently tested positive upon arrival in South Korea have all tested negative for Covid-19.
The Ministry of Health says this reinforces the current low risk of the case to New Zealand.
According to the Ministry of Health, the individual left New Zealand on July 21 and arrived in South Korea on July 22 after transiting through Singapore.
The traveller had no symptoms but returned a positive test on arrival.
South Korean authorities informed the Ministry of Health that based on their initial investigations, they suspect the traveller was infected during the transit in Singapore airport.
The Ministry of Health began contact tracing on the case here due to an abundance of caution.
"Contact tracing of passengers on a domestic flight this person was on from Auckland to Christchurch and other possible close contacts continues," the ministry said in a statement today.
"All related tests undertaken to date have returned a negative result, including tests results we have to date from border staff at Christchurch airport. Further testing is underway.
"Those identified as close contacts within the 48 hours before the case had their positive test are being asked to self-isolate for the balance of their 14 days.
"Any casual contacts do not need to self-isolate but are being asked to be tested if they develop symptoms consistent with Covid-19 over the 14-day period."
The Ministry of Health says its awaiting the result of a second PCR test of the man from South Korea.