Earlier on Monday, Ardern urged the woman to come forward.
"That is by far the simplest path from here," Ardern said at the 4pm press conference where it was announced Auckland would remain in the same alert level 3 restrictions for a further week, while Northland and parts of the Waikato could move to level 2 on Friday.
Ardern said health officials and police were "really pulling out all the stops" to find the traveller.
"I feel the same frustration that everyone else feels," she said.
"They are refusing to co-operate, it is beyond irresponsible, it is dangerous."
Earlier today, director general of health Dr Ashley Bloomfield confirmed the person "is not travelling around Northland at the moment".
Northland will remain in alert level 3 for a further three days, with Cabinet reviewing these settings on Wednesday, at the same time they will review settings in Waikato.
Ardern said yesterday it was unclear if the second traveller was infected with the virus.
On Friday night Northland moved back into alert level 3, after her travelling companion, an Auckland woman, tested positive. That woman is also back in Auckland and has been in MIQ but has been refusing to cooperate with officials on her movements.
On Sunday it was revealed officials had contacted the second woman who was with a Covid-positive case on a trip from Auckland to Northland. Until last night, they had been unable to locate her.
The Ministry of Health has confirmed that 19 close contacts are associated with the positive case so far.
Almost 4000 Covid tests have been carried out in Northland over the past four days.
Five testing sites are open today, in Kaitāia, Whangārei, Dargaville, and Kerikeri.
These areas also have vaccination sites running.
