A specialist search group from the Christchurch police has joined the inquiry into what killed a young man driving towards Wanaka last week.
Rutger Hale, 22, was driving along State Highway 6 on Thursday morning when an object flew through his windscreen, hit his head, and went through the rear windscreen. The mystery object has not yet been found.
The squad of six arrived on Tuesday and is searching the roadside with specialist equipment.
A police spokesperson says the Christchurch staff expect to be working at the scene for a couple of days.