According to a newspaper report, Dhillon while admitting to disposing off the toddler's body had denied deliberately injuring the child.
The accused, who was staying with the child's parents, told the police that he had accidentally knocked the child unconcious on Thursday, Mar 4, at the house in David Street, Lalor.
He claimed he panicked and bundled the unconscious boy in the boot of a car, adding that he drove around for three hours before dumping the body 20 kilometres away in Oaklands Junction without checking if the three-year-old was alive.
The Victorian police said that 3-year-old Gurshan could have been saved if he had been administered medical aid on time instead of being left trapped in the boot of a car.
A newspaper report said that the car will be tested by forensic experts to check whether the boy died of suffocation or by carbon monoxide poisoning from a faulty exhaust.
Gurshan's father, Harjit Singh Channa has sought stringent action against the accused.