A 73-year-old woman has been arrested after a three-year-old boy died following a hit-and-run incident in Melbourne’s west. 

Police believe the boy ran onto McIntyre Road in Sunshine North after breaking away from his mother about 6.30pm on Thursday.

He was hit by a red sedan that failed to stop.

The boy was critically injured and taken to hospital, where he died overnight.

Police early on Friday morning issued a plea for the driver to come forward.

It was possible the driver did not realise their car struck the toddler, Superintendent John Fitzpatrick said.

“That’s largely due to the size and the age of that little guy. It’s a tragic set of circumstances,” he told Melbourne radio 3AW.

The 73-year-old woman from Heathcote Junction, north of Melbourne, handed herself in to police on Friday morning.

She will be interviewed by police. A red sedan has been seized and will be forensically tested.

Police have asked anyone with information to contact Crime Stoppers.