THE family of Matthew Mitchell, who died of a head injury sustained at Sandy Beach four years ago, have joined police in renewing an appeal for information.
Mr Mitchell died after being struck by a motor vehicle an inquest found last year.
On August 17, 2013, Mr Mitchell who was 30 at the time was found lying unconscious on Graham Dr with a serious head injury after attending a party.
He was later transferred to Sydney's Royal North Shore Hospital where he died of complications from his head injury on September 19.
In Mr Mitchell's death inquest NSW Deputy State Coroner Helen Barry wrote: "I am satisfied on the evidence that Matthew was killed as a result of a motor vehicle collision."
But she wrote there was "insufficient evidence" to identify the person driving the vehicle.
After extensive investigations and public appeals by police, no one has been charged in connection with Mr Mitchell's death.
Coffs/Clarence Local Area Command Crime Manager, Detective Inspector Darren Jameson, said officers in Strike Force Dartmoor were doing all they could to ensure someone was brought to justice, but community help was needed.
"We are particularly interested in speaking to anyone who may have knowledge of the vehicle and/or driver responsible for the collision with Matthew," Det Insp Jameson said.
"We believe the driver of a vehicle travelling south on Graham Drive about 10.50pm on Saturday, August 17, 2013, may hold the key to this matter."
Strike Force detectives are confident there are people out there who have information but have been reluctant to come forward.
The investigation will remain ongoing with the Mitchell family seeking answers.
"Someone must know something so I urge you to pick up the phone and call us - you can do this anonymously through Crime Stoppers," Det Insp Jameson said.
If you have any information, visit the Crime Stoppers website or phone 1800 333 000.