Three people are believed to have breached the NT's border controls by arriving over the Camooweal border from a declared coronavirus hotspot.
This group has been later found and quarantined, and a second group who they came into contact with has also been isolated.
Police have launched an investigation into the alleged border control breach on Monday.
Three men, aged 26, 27 and 29 plus a a 28-year-old female traveled into the Northern Territory by road in a private vehicle through a border control point on the Queensland and NT border.
A member of public sounded the alert telling police the men had traveled from a declared COVID-19 hotspot within the previous 14 days.
The NT's borders are open again but not to declared hotspots such as Victoria, Sydney and other areas of NSW.
Police are now tracing where the group had actually traveled from.
The four people have been located in Alice Springs where they have been isolated pending further inquiries being conducted.
Environmental Health Officers immediately identified two females, aged 19 and 24, and a 27-year-old male who had recent contact with the group in Alice Springs and these three are also in isolation.
COVID-19 testing and contact tracing in relation to all seven people is currently underway.