A police safety campaign in Christchurch has found that almost half of all of the child car seats checked were unsafe.
Police checked 300 cars, containing 275 children, over a period of two weeks.
All but two children were in a restraint, but 135 of the 273 car seats checked were not up to the required standard, or correctly installed.
Senior constable Grant Neal says the correct use of a child restraint can make the difference between life and death.
The most common faults were tether straps not attached to anchor bolts, seatbelts not correctly routed through the car seat and children having out grown their seat.
Mr Neal says the Transport Agency website has a list of child restraint technicians who can check car seats free of charge.
