A 27-year-old woman is fighting for her life in Christchurch Hospital after falling from a moving vehicle early this morning.
The woman was a passenger in a maroon Toyota Hilux ute that was being driven by her partner when the incident happened in Halswell.
Detective Sergeant Jason Stewart says her partner has been spoken to by police and is helping them with their investigation.
Police said the car was driving at about 70km/h when the incident happened on Branston St.
The woman is in a critical condition with serious head injuries.
Her immediate family have been advised, but her name will not be released until further family members are told.
Police have called for witnesses, who may have seen a maroon Toyota Hilux twin cab utility driving on Halswell Junction Road near Shands Road at about 1.45am, to phone Christchurch central police on 03 363 7400.