At 8.54pm on Sunday, emergency services were called to a single-vehicle accident near the Princes Highway, Bombo.
Occupants of a northbound car had veered off the highway and crashed into scrub between the highway and an offramp to Bombo Beach at Hutchinson Avenue.
The vehicle, which was damaged extensively, had been abandoned by the time emergency services arrived, including NSW Police from the Lake Illawarra Command and NSW Fire and Rescue Service firefighters from Kiama.
Police and firefighters launched a search of the area, deploying police helicopters and pointing thermal cameras into nearby bushland.
By Monday at 10.30am, no arrests had been made, and police investigations continued.
Local residents with any information to offer police are advised to contact Crime Stoppers on 1800 333 000.