The man who died when his truck tipped near Waverley on Monday has been named by police.
He was Anthony Douglas Stubbs, 73, of Waverley.
The crash happened on Kohi Rd about 11am and the road was closed until that evening as police investigated.
Whanganui Sergeant Colin Wright said police had notified Stubbs' partner and daughter.
He said although it looked as if Stubbs had had a "medical event" leading up to the crash, that wasn't certain and a post-mortem examination was being carried out in Palmerston North.
"Basically it's happened just after a moderate left hand bend just after Hughes Rd," Wright said.
"It looks like he's basically lost control after the bend and overturned. We don't know whether it's a medical event. That's what we were initially told at the scene."
No other vehicles were involved in the crash.
Stubbs had been travelling between Waitotara and Waverley before deciding to take Kohi Rd.
Wright said there didn't appear to be any witnesses who saw the truck tip over but he appealed for any sightings of Stubbs' orange Nissan tipper around the time of the crash.
The truck will be examined by the police's commercial vehicle safety team and the serious crash unit from Palmerston North will also investigate.