There is growing concern for Auckland woman Michelle Simpson after two-and-a-half days of "extensive searching", say police.
Police said the 50-year-old, who has "a mental impairment", may have been disoriented and got lost.
It was unlike her to leave the house without a caregiver, but police said there was nothing to suggest foul play was a part of the disappearance.
She was last seen walking along Wairere Road in Kumeu at around 11:30am on Monday wearing a gold-coloured cardigan, a red floral dress, and possibly a woven floppy green and blue hat.
She has not been seen since then.
Police and Land Search and Rescue teams have searched extensively around the area in the last 48 hours, but have so far found no signs of Ms Simpson.
A helicopter has also been used, but police said the rural location and dense bush is making search efforts more challenging.
Inspector Bruce O'Brien said police "will continue to search the area by land and by air, and today we have widened our search area".
Ms Simpson was last seen with a green drink bottle and floral tote bag.
Police want anyone who may have seen the items on their property or anywhere near Wairere Road to contact them.