A 28-year-old motorcyclist from Moruya was killed in a collision with a car just north of Narooma on Thursday night.
Detective Inspector Justin Marks said the man was riding his bike northbound when, at about 9.15pm, for unknown reasons he crossed the centreline of the Princes Highway just north of the Mort Avenue, Dalmeny, turn-off.
The man, who has worked in Narooma for some time, collided with a southbound Holden Commodore, was ejected from the motorcycle and was thrown some distance before coming to rest on the side of the highway.
Both his 1000cc Kawasaki road bike and the Commodore sustained significant damage.
Witnesses performed CPR on the motorcyclist before ambulance paramedics arrived on scene but the man died on the way to Moruya Hospital.
A crime scene was established with both local officers and forensic investigators, and the northbound lane was closed most of the night.
Roads and Maritime Services workers and volunteers from the Dalmeny Kianga Rural Fire Service brigade directed traffic during the investigation.
The 26-year-old driver of the Commodore was also taken to Moruya Hospital for mandatory blood and urine tests, while the Narooma police will prepare a report for the Coroner.
Inspector Marks said police could not rule out speed or any other factor at this time.
The stretch of highway just north of the Dalmeny turn-off has seen a number of fatal accidents in the past few years.
The motorcyclist came to rest mere metres away from the roadside memorial to Narooma woman Chantell Eldridge, killed on the same corner of the Princes Highway in 2008.