A 15-year-old boy is dead after his dirt bike collided with a car in Werribee on Wednesday evening.
The Werribee boy collided with a BMW sedan at the corner of Market and Meek streets about 4.50pm.
Ambulance spokesman Paul Bentley said paramedics rushed the boy suffering critical head injuries to the Royal Melbourne Hospital where he remained overnight, but he died on Thursday morning.
Wyndham police are investigating the circumstances surrounding the collision.
Police spokeswoman Belinda Batty said investigators were questioning the driver of the sedan.
Ms Batty said police were appealing for witnesses and anyone with information about the crash to contact Crime Stoppers on 1800 333 000.