A motorcycle rider, who was helped by bystanders after his clothing caught fire in a crash at Kogarah, allegedly fled the scene, leaving his teenage pillion passenger behind.
Police later arrested and charged a man, 20, with several offences, including take and drive conveyance, negligent driving occasioning grievous bodily harm, fail to render assistance and drive while disqualified.
A police statement said a Suzuki DRZ400 motorcycle and Hyundai Excel were involved in a crash about 5am on Monday on Princes Highway, near Gray Street, Kogarah.
"Bystanders helped the rider to remove clothing on fire, before he allegedly fled the scene," police said.
"His pillion passenger, a 15-year-old boy, was treated at the scene for head injuries, and later taken to Westmead Children's Hospital,where he remains in a serious condition.
"The driver, a 56-year-old man, was uninjured.
"Officers from St George Police Area Command attended and commenced a search of the surrounding area, with assistance from the Dog Unit, however, the rider was not located.
"Following extensive inquiries, officers from Fairfield City Police Area Command stopped a vehicle on Corona Road, Fairfield West,and arrested the rider, a 20-year-old man.
"He was taken under police guard to hospital, where he was treated for a burn to his leg.
"The man was later released and taken to Fairfield Police Station, where he was charged with take and drive conveyance, negligent driving occasioning grievous bodily harm, fail to render assistance and drive while disqualified.
"He was refused bail and is due to appear in Fairfield Local Court on Wednesday 16 September."