A 27-year-old woman is in a critical condition in Christchurch hospital after falling from a moving vehicle in the early hours of the morning.
The woman suffered head and leg injuries in the incident in the suburb of Hornby about 2am on Sunday.
Detective Sergeant Jason Stewart says the woman fell out of a utility vehicle her partner was driving on Halswell Junction Road near Shands Road.
Police are gathering more information and say the woman's partner is cooperating.
They want to speak to anyone who saw the maroon Toyota Hilux twin cab ute in the area early on Sunday morning.
Mr Stewart says the woman is surrounded by close family in hospital and her name won't be released until further family members have been told.