A 32-year-old man from Cranbourne West attended Springvale police station on Thursday night but he has been released pending further inquiries.
On Friday morning the boy remained at the Monash Medical Centre and was being treated for serious injuries in a stable condition.
Resident Tommy Do returned home early Thursday evening to find the road blocked off and the street swarmed with police cars.
About 9.30pm, police officers knocked on his door and asked to take CCTV footage from his security camera out the front of his house which is believed to have captured the incident.
He said investigators told him the car was believed to be travelling at up to 70km/h when it struck the boy.
Mr Do, who has lived on the street for about two months, said he often saw the little boy riding his bike with his younger sister across the road from his house.
“It’s really awful,” Mr Do said. “As a father myself, I can’t imagine how his parents and family must be feeling.”
Police say they believe the driver of the dark-coloured sedan did not stop and the car would likely have damage to the passenger side headlight.
The investigation remains ongoing, and police are appealing for witnesses and anyone with footage of the crash to come forward.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au
Simone is a breaking news reporter for The Age. Most recently she covered breaking news for The Australian in Melbourne.
Melissa Cunningham is The Age’s health reporter.