A 41-year-old Christchurch woman is in critical condition after suffering severe head injuries in an assault early this morning.
Detective Senior Sergeant Corrie Parnell says police were called to Worcester Street, Linwood, shortly after 1am.
At the house, they found a woman with severe head injuries. She is now in a critical condition in the intensive care unit at Christchurch Hospital.
Mr Parnell says a man has come forward to police and is helping investigators with enquiries.
"Although we are speaking to a number of people in connection with the incident, we are not looking for any other individuals at this point,'' he said. "We believe the man was known to the victim.''
Mr Parnell said a scene examination is underway at the property and is likely to continue for several days.
Police are also seeking information about the movements of a car which they believe may be related to the assault.
"The vehicle of interest is a green Toyota Camry sedan, registration number ST 8323. We are keen to hear of any sightings of this vehicle during the past 24 hours.
"It may have been in the Sumner and Waimakariri River areas, as well as in Christchurch city, during that period.''
Anyone with information about the car is asked to contact Christchurch police on (03) 3637400. Alternatively to provide information anonymously, contact Crimestoppers, 0800 555 111.