A 42-year-old woman has been arrested and charged with kidnapping after a woman was found on the side of a road in Dome Valley, north of Warkworth, on Monday.
The arrested woman will appear in the North Shore District Court tomorrow. She is the third person to be arrested over the incident.
A 28-year-old woman and a 38-year-old man appeared in court this week.
The 28-year-old woman is charged with two counts of kidnapping and one count of threatening to kill. She has been granted name suppression and will be remanded in custody until her next appearance on Tuesday.
The man has been charged with kidnapping. He was granted name suppression and denied bail over concerns he could make contact with others involved. Police say the man is not known to the victim.
Police say more arrests are possible as the investigation continues.
The victim remains in Auckland Hospital in a serious but stable condition. She was found with her wrists and ankles bound after the alleged kidnapping and serious assault.