Detective Senior Sergeant Craig Sheridan said the driver picked up a male hitch-hiker between 5 and 6pm from State Highway 1 south of Ōtaki before dropping him off in Paraparaumu.
"We believe the driver may have been visiting family in Levin and was travelling back towards Wellington," Sheridan said.
"We are hoping this driver can assist the investigation team as we piece together a timeline of events relating to this inquiry."
If you are the driver, or can help locate him, please contact police on 105 and quote file number 200517/3200.
Neighbours of the suspected homicide victim said he was a "really nice guy" who lived a quiet life.
One neighbour said the victim was a quiet man he had spoken to a few times in passing and never had any problems with.
"We didn't communicate much at all, really. He kept to himself and I kept to myself."
Another neighbour said she lived close enough that she could reach out the window and touch the victim's house, but despite being home last night she heard nothing next door.
The first she knew of the death was when she woke up the morning after his death to see the house "alive with police".
"We live in a quiet little town," she said.
"I'm surprised because I didn't see him very often, but he was a nice guy. There was a couple of nice other people."