A third person has been arrested over an assault on a woman found with serious head injuries on the side of a road at Dome Valley last Monday.
A 42-year-old woman will appear in the North Shore District Court tomorrow charged with kidnapping.
A 28-year-old woman and a 38-year-old man had already been charged with kidnapping over the incident.
The police said there could be further arrests as the investigation continues.
The victim remains in Auckland Hospital in a serious but stable condition.