A six-year-old boy has been seriously injured after the car he was in was hit by a utility vehicle in the breakdown lane at Wilton.
Emergency services responded to reports of a two-vehicle crash in the southbound lanes of the Hume Highway near the Picton Road interchange about 12.45pm.
Police were told a white Nissan Navara driven by a 47-year-old man with three passengers - a 30-year-old woman, six-year-old boy and a 10-month-old boy - was stopped in the break down lane when it was allegedly struck from behind by a white Great Wall utility driven by a 26-year-old man.
Camden officers secured a crime scene which was examined by specialist police from the Crash Investigation Unit.
The older child was treated at the scene by paramedics before being taken to Westmead Children’s Hospital in a serious but stable condition.
The woman and the baby were treated for minor injuries and taken to Westmead Hospital as a precaution.
The older man was not injured.
The 26-year-old man, who suffered minor injuries, was arrested and taken to Campbelltown Hospital for mandatory testing.
He was later taken to Camden Police Station where he was released pending further inquiries.
As inquiries continue, police are appealing for anyone who may have witnessed the crash, or has dashcam footage, to contact Crime Stoppers on 1800 333 000.