Police say several vehicles drove past a fatal motorcycle accident without stopping near Oamaru in the early hours of Thursday.
The motorcyclist, believed to be an 18-year-old man from South Canterbury, crashed just before 3am on State Highway 1 at Richmond. He died at the scene.
Police were not notified for about half an hour, during which time a number of cars drove past the crash site.
They would like to speak to anyone travelling on State Highway 1 in the Oamaru area between 3.30am and 4.30am on Thursday.