Major Collision Investigation Unit detectives are investigating after a serious collision in Carlton on Saturday, 11 March.
Emergency services were called to reports of two-vehicle collision on Lygon Street just before midday.
Investigators have been told a Volkswagen Pussat was seen driving erratically before crashing into an Alfa Romeo which subsequently spun out of control and struck a pedestrian.
The male pedestrian was taken to hospital with life threatening injuries.
A female teenager in the Alfa Romeo has been taken to hospital with life-threatening injuries while the other two occupants, a man and woman, were transported with non-life-threatening injuries.
The driver of the Volkswagen was detained by bystander until police arrived and has been taken to hospital under police guard with non-life-threatening injuries.
The exact circumstances surrounding the collision are yet to be determined and investigations remain ongoing.
Anyone who witnessed the incident, has CCTV, dashcam footage or any other information that could assist investigators is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.auExternal Link
