The person who killed helicopter pilot Ian Pullen and fled would know what they have done, one of the region's senior police says.
Mr Pullen was found dead beside a road near Singleton just after 5.30am on September 29, a day after he arrived to be on standby for work as a water bomber for the Rural Fire Service.
Investigators quickly identified the husband and father from New Zealand as a hit and run victim and police Strike Force Awabakil has been searching for the perpetrator since then.
Hunter Valley commander Superintendent Chad Gillies renewed the police appeal for information about Mr Pullen's death on Thursday, on the eve of the six month anniversary of the 43-year-old's death.
Police want anyone with information about what happened in the Carrington Street area in Glenridding in the 90 minutes leading up to 5.30am on September 29 to contact them.
"We know that Mr Pullen was struck by a vehicle and we also know that the person driving that vehicle would be well aware and they've decided not to stop and render assistance and obviously not report it to authorities," Superintendent Gillies told the Newcastle Herald.
"That's what our investigation has revealed so far, that the person involved would be aware they struck a person and secondly they didn't stop."
Superintendent Gillies said investigators now believed a white, dual cab ute with a black front bumper bar was linked to Mr Pullen's death.
He said police also believed the vehicle in question had "some front end damage", consistent with hitting a person.
"Anyone that may know a vehicle to either be in that area or in the outskirts of the Hunter that has similar description or has been repaired at some point, we'd be very interested to hear from those people," he said.
"I guess the tragic aspect from our perspective was Mr Pullen was in the Hunter trying to assist in the bushfire season.
"We owe it to him and his family to try to get some closure."
Mr Pullen's wife, Vicki, also appealed for anyone who could help with the investigation to contact police.
"I'm just hoping that someone will have the decency to come forward," she said.
"It will give our family closure and let us be able to put Ian to rest."
Anyone with information can contact Crime Stoppers on 1800 333 000.