Police are investigating a carjacking in Laverton North early this morning.
Investigators have been told a vehicle bearing stolen plates side-swiped a truck before rolling and crashing into a barrier on the Princes Freeway at Laverton North at about 12.15am on Thursday October 19.
The three occupants managed to walk away from the crash before the vehicle caught fire.
They then threatened a motorist who had stopped to offer assistance and stole his Mercedes sedan.
The victim was not physically injured.
Investigations into the incidents remain ongoing and police are warning anyone who spots the back 2012 Mercedes with registration 1SR9OX to call Triple-Zero (000).
Those who witnessed the initial incident or have any other information that could assist police are urged to contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au