The search for missing jogger Kim Bambus is entering its fourth day.
Police are still keeping an open mind on what has happened to Bambus.
This morning police said Bambus was still missing and the search would resume at first light.
At a press conference on Sunday, Detective Inspector Hayden Mander said people have survived longer than this. But as time goes on they have greater concern for the 21-year-old.
"We very much remain hopeful that she remains alive.
"We really don't know what's happened to Kim ... All we know is that she's missing and we're trying to find her.
"There are an endless number of possibilities."
Bambus told her friends she was going for a run at the west coast Auckland beach Piha on Friday morning but she never returned.
Her worried friends drove out to Piha and found her car with her cellphone still inside parked at the entrance to Ahu Ahu Track (Mercer Bay loop track), which traverses the vast cliff faces above the beach.
Police and search and rescue volunteers spent Saturday combing the area, with teams abseiling down the sheer cliffs to look for any sign of Bambus. Helicopters also scanned the coastline, while Bambus' family and friends anxiously waited at the track's entrance hoping for news.
Her sister, Storm Bambus, said she got a call on Friday night from one of Kim's close friends saying that she had not returned to her Ponsonby flat.
"I drove down and obviously the search and rescue started. There were helicopters all [Friday] night, dogs searching for her," she said.
"We're assuming that she went for a run or a walk there and she hasn't been heard of since."
Kim had started working as a registered nurse at Middlemore Hospital a couple of months ago.
The family is from the Bay of Islands but Kim moved to Auckland about four years ago.
Kim's parents were on their boat off Great Barrier Island when they received news of Kim's disappearance and sailed through the night to get back to Auckland. They joined the vigil at Piha on Saturday afternoon.
Bambus was wearing a dark jacket, pink exercise top, black shorts and black and white Nike running shoes.
Her hair was tied up in a ponytail and she was carrying a large water bottle.
She was last seen in Countdown in Williamson Ave, Ponsonby, buying snacks at 9am on Friday morning.
Mander urged anyone who had a CCTV system in and around Log Race Rd and the Ahu Ahu track or anyone who had used the tracks in those areas at any time on Friday to get in touch.
"Regardless of what time of day or evening you used those tracks, we'd like to hear from you please.
"If Kim isn't found [Sunday] then we'll be back tomorrow continuing the search for her."
He said the track was commonly used and it was a possibility Bambus had made it to the beach area on the other side.
"We're not ruling out anything."
Call Police on 0800 528 337 with any information.
The 19-year-old disappeared without her wallet or mobile phone.