A Darwin resident, aged in his 30s, has the virus.
He came back to Australian from overseas, and completed two weeks of quarantine in Melbourne.
But before returning home to Darwin, he stayed with family in one of the coronavirus hotspot areas of Melbourne.
Northern Territory Health Minister Natasha Fyles says the man followed regulations, and has had minimum contact with the community in the Northern Territory.
As part of that contact tracing, authorities are seeking anyone who was a passenger on Qantas flight Q-F 8-3-6 from Brisbane to Darwin on Monday, 29 June.
