Major Collision Investigation Unit detectives are investigating a collision which occurred in Tarneit on 13 August.
Police have been told a man was struck by a vehicle near Leakes and Begonia roads about 6.30pm.
He was airlifted to hospital with life-threatening-injuries.
The alleged driver of the vehicle was arrested at a property on St Nicholas Court a short time later.
He is currently in police custody and is expected to be interviewed later today.
The exact circumstances surrounding the collision are yet to be established and the investigation is ongoing.
Anyone who witnessed the incident, with CCTV/dashcam footage or any information that could assist police is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au.
