Police are investigating a three-vehicle collision in Clarkefield on 13 December.
It is understood a Jeep Wrangler, a Mazda 3 and a Toyota Corolla collided on Melbourne Lancefield Road about 11.45am.
The 50-year-old female driver of the Toyota was airlifted to hospital with critical injuries.
The male drivers of the Jeep and Mazda, aged and 33 and 35, were both taken to hospital with non-life-threatening injures, along with a female passenger of the Mazda.
The investigation remains ongoing.
Clarkefield CFA posted to its Facebook that responders were on the scene, and encouraged the public to avoid the area.
The road remained closed until 10.30pm on Saturday, with drivers asked to detour through Riddells Creek from Sunbury while road closures were in place.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppers.vic.com.au
