Investigators examined the scene and interviewed “a number of people” in relation to the incident.

Police have spoken with “a person of interest” and a spokesman said this person was assisting with their inquiries.

“Police would like to speak to anyone who was travelling on State Highway 12 this morning between 7:45am and 8:45am,” the spokesman said.

“Motorists who may have dashcam footage or saw either the vehicle, or a person walking, on the road near rapid numbers 6700-6900 are urged to contact police if you have not already done so.

“This area of interest to police is about 4km south of the Waimamaku township.”

Anyone offering information could do so by calling 105 or going to www.police.govt.nz/use-105 and referencing Operation Number of file number 240801/3234.

Information can also be offered anonymously via Crime Stoppers on 0800 555 111.

SH12 was closed for almost 10 hours after a report of a serious crash, the New Zealand Transport Agency said.

Raphael Franks is an Auckland-based reporter who covers breaking news. He joined the Herald as a Te Rito cadet in 2022.