Greensborough Highway Patrol members are hoping to speak to the driver of a vehicle who stopped to assist after a hit and run in Epping on 22 February.
Investigators have been told a 58-year-old school crossing supervisor was removing flags from a Findon Road school crossing about 9am when he was struck by a silver vehicle.
The collision caused the victim to fall onto the road and roll into the gutter.
The South Morang man was later transported to hospital with upper body injuries where he remains.
It is believed the silver vehicle stopped a short distance away from the collision scene before driving away without rendering assistance.
Police believe the offending vehicle was a small silver or grey sedan with Victorian registration plates.
The female driver is believed to have been Caucasian, approximately 50-years-old with light brown hair.
Investigators have received information that a female driver in a maroon/burgundy coloured vehicle is believed to have been driving directly behind the offending vehicle.
The woman, believed to be aged in her 40s, stopped to assist the school crossing supervisor but was unable to remain before police arrived.
She is described as having dark brown shoulder length hair, possibly of European descent and told other witnesses that she was on her way to work.
Anyone who witnessed the collision, has dashcam footage or CCTV from nearby is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au.