Police are working to piece together events that lead to the death of a man who came off his motorcycle north of Whanagrei this morning.

He was found dead by a member of the public on State Highway 1 at Kauri around 4am.

His motorbike was discovered nearby in a ditch, police said.

Senior Sergeant Cliff Metcalfe said the man was discovered by a woman who passed by the crash site in her car, and pulled over.

Advertisement

He said police were still trying to piece together how long the rider had been on the road for before he was discovered.

"We have no idea at this stage, inquiries are obviously continuing. It's a bit of a blank canvas... until we talk to all the witnesses we don't know."

Police would speak to several "witnesses" who had passed the scene of the crash, and others who had called in reporting hearing motorbikes in the area, Mr Metcalfe said.

"Obviously at the moment our priority is at the scene and getting that cleared so we can open the roads.

"Then there will be quite extensive inquiries into what happened on the road, and what actually lead up to him being on the road."

Police were yet to identify the man, Mr Metcalfe said.

SH1 north of Apotu Rd was closed and diversions were in place via Saleyards Rd.

The road was expected to be reopened sometime this morning.

Advertisement

The serious crash unit remains at the scene.