Police are appealing to the driver of a vehicle seen near the fatal shooting of a road worker to come forward.
Hamilton man George Charles Taiaroa, 67, was shot while manning a stop-go sign on Tuesday afternoon.
The shooting happened near Tokoroa on Tram Rd, a short stretch of rural road in the Kinleith Forest area which bridges the Waikato River.
Witnesses saw what looked like a blue Jeep Cherokee stop by Mr Taiaroa and speed away towards Tirohanga Rd as Mr Taiaroa fell to the ground.
Dozens of calls had been made to the investigation team and there was a regular and steady flow of information, particularly around sightings of the vehicle.
Detective Inspector Mark Loper said police had pieced together sightings of the 4WD immediately after the incident and were able to track it through the web of rural and forest roads to the main road that runs between Mangakino and Benneydale.
"There are a number of routes the vehicle could have taken from that main road and a key focus is tracking its movements from that point.
"I also want to appeal directly to the driver of that vehicle to come forward; likewise anyone who knows, or suspects, who killed Mr Taiaroa. Anyone who contacts us can be assured they will be doing so in complete confidence."
The Police National Dive Squad would be scouring the Waikato River today near where Mr Taiaroa was killed, looking for evidence that might help the homicide investigation.
It was not known how long the team would take to search the river, a police spokeswoman said.
"The dive search is part of the scene examination process looking for anything that might assist the investigation," she said.
She would not confirm if the team was looking for a weapon in the river.
Police investigating the shooting of Mr Taiaroa said they were encouraged by the positive response from the community.
Mr Taiaroa's body was removed from the area on Wednesday morning and was yesterday taken to Auckland for a post-mortem examination, which confirmed he was fatally shot.
His funeral will be held tomorrow near Levin.
Detective Inspector Tim Anderson said it was still too early in the investigation to speculate about motives.
No one had been arrested at this stage.
"Currently we have over 30 experienced staff assisting with completing area inquiries."
Mr Anderson said he believed the homicide was an isolated incident.
Police have today set up a free hotline dedicated to the investigation.
Anyone who had information that might help in the investigation was asked to contact 0800 Kingswood or 0800 546 479.
All calls would be treated in confidence, a police spokeswoman said.
People with information could also contact Taupo police on (07) 378 6060, or anonymously contact Crimestoppers on 0800 555111.
- APNZBy Rebecca Quilliam Email Rebecca