Almost a year after he died, the police are no closer to solving the riddle of what killed Rutger Hale.
Mr Hale died when an object flew through the windscreen of his car as he travelled to work near Wanaka in October last year.
While the matter has now been referred to the coroner, the police are appealing for any new information that may help them to determine what happened.
The police carried out extensive work on the 22-year-old's Subaru vehicle but were unable to identify the object.
Mr Hale's girlfriend, Danielle Oylear, who was in the car at the time, has previously appealed for the driver of a white ute which passed the couple to come forward.
She said a brick-like object appeared to come from the ute before the impact.