Police are searching for clues about what led up to the discovery of a man's body on State Highway 1, south of Waipu.

Detective Sergeant Dave Wilkinson said the body was found on the section of State Highway 1 between the intersections with Waipu Gorge Road and State Highway 12. The area is about 13 kilometres south of Waipu.

Emergency services were called to the scene just before 9am on Saturday, and investigators found signs the man was probably struck by a vehicle.

Wilkinson said they want to speak to anyone who was in the area of Brynderwyn Summit and Artillery Road between 7pm and 10pm on Friday.

They would also like to hear from anyone who had dashcam footage of those areas.

Anyone with information can contact police on 105.