The search for Kim Bambus has been scaled back, with police suggesting there is no evidence to suggest foul play.
Bambus, a registered nurse at Middlemore Hospital, hasn't been seen or heard from since Friday morning.
Her car, with her cellphone inside, was found parked at the entrance to the Mercer Bay loop track near Auckland's west coast beach of Piha.
Detective Inspector Hayden Mander, of Waitemata Police police search and rescue officers have been looking near the Mercer Bay cliffs, shoreline, and combing the tracks around Piha.
"There has also been a team of investigative staff looking into Kim's movements and activity in the weeks prior to last Friday," he said, adding it was "standard practice for a missing person operation of this nature".
"A vast amount of information has been gathered to this point about Kim's activities, which includes checks with health professionals, as well as checks of her internet and phone searches up until last Friday.
"Based on this information, the search has been focussed on the Mercer Bay cliff area."
He said there was no evidence in the information gathered that suggests any foul play.
"Though enquiries have also looked at previous missing person reports in that area, there is currently nothing to indicate any link whatsoever with any other missing person case."
Cherie Vousden, 42-year-old North Shore mother, went missing on December 22, 2012. She was last seen walking along the Mercer Bay loop tack.
"Sadly we have now reached the point where all possible search options have been exhausted, and as such, the search will be scaled back," Mander said.
Bambus' father, Bernie Bambus, thanked search and rescue and police for their efforts.