A fourth person has been arrested after a woman was found seriously injured on the side of a road north of Auckland last week.
A 29-year-old woman will appear in North Shore District Court on Wednesday, charged with kidnapping.
Two women and one man have so far appeared in court over the incident.
Police say they haven't ruled out making more arrests.
The victim, aged in her 20s, was found by a member of the public last Monday morning in Dome Valley and was flown to Auckland Hospital.
She is still in hospital in a serious but stable condition.