Health authorities have managed to contact the person they think travelled with the Covid-positive woman who was in Northland.
However, the person has not been located yet.
It comes after Northland was sent back into Alert Level 3 on Friday night after the woman, described by Covid-19 Response Minister Chris Hipkins as being "uncooperative", was confirmed as a positive case.
She first returned a "weak positive" Covid-19 test on Wednesday while in Whangārei. She was re-tested in Auckland on Thursday. That test came back positive.
Hipkins said the person travelled "extensively" while in Northland between October 2 and October 6.
"They are believed to have travelled around the region, including in Whangārei, Kamo, Paihia and Kawakawa, before returning to Auckland," he said.
"They have not been particularly forthcoming with their movements."
To date, Comfort Hotel Flames in Whangārei, the Department of Conservation campsite at Uretiti, Pepe's Dairy in Onerahi, Z Kensington and BP Connect Wylies have been identified as locations of interest in Northland.