"When I saw him, he looked like a nice person who was maybe 19 or 20," Mr Reddy said on Monday.
"When police told me he was 12 ... I was shocked." Det Insp Fehon confirmed that "despite being 12 years old he is about six foot tall".
Mr Reddy said the boy was driving what looked like a white Hyundai SUV. Det Insp Fehon said the car had suffered some damage.
"So it appears (the boy) did have an accident while driving," she said. Highway patrol officers spotted him at Broken Hill about 11am on Saturday. The boy was arrested and taken to Broken Hill police station before being released to his distressed parents. Police said they were "extremely relieved" to see him.
The family are expected to arrive back on the state's mid north coast on Monday afternoon, with the boy to be questioned by local detectives there. It's likely he'll be charged under the Young Offenders Act with three offences, including the illegal use of a car, unlicensed driving and failing to pay for petrol.
Some people on social media praised the boy's escapade, calling him a "pretty clever kid" who deserved a "gold star for effort".
"Clearly he's a top driver. No ticket in 1300km," Lou Steer wrote on Facebook. But Det Insp Fehon said the boy should not be commended.
"Not only was the child's life at risk but all the people he went past and came in contact with," she said.
"He was lucky he had an escape (after his accident).
"But so did all the motorists on the way from Kendall to Cobar. They all had a lucky day as well."
- AAP