A 12-year-old boy who drove 1300 kilometres across New South Wales on his own in the family car managed to evade suspicion partly because he looks much older and is 'about six foot tall'.

After leaving the state's east coast on Friday morning, the boy topped up at a Cobar service station without paying for the fuel on Saturday morning.

He was only stopped a few hours later in Broken Hill when police noticed the car's bumper dragging on the ground.

The 12-year-old boy who drove across New South Wales on his own in the family car stopped to get petrol about 6am on Saturday at a Caltex service station in Cobar (pictured)

The boy managed to evade suspicion partly because he looks much older and is 'about six foot tall' (stock image)

The boy's attempt to drive to Perth started after 11am on Friday when he took off from the family home in Kendall, near Port Macquarie.

'His parents reported him missing immediately after he left home, so they were looking for him,' Detective Inspector Kim Fehon told AAP on Monday.

The boy stopped to get petrol about 6am on Saturday at a Caltex service station in Cobar.

Manager Vamshi Reddy said the boy took $19 worth of fuel but left without paying.

'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.

The boy drove 1300 kilometres across New South Wales, from the state's north coast to the state's outback (stock image)

The manager of the Cobar Caltex service station said the boy took $19 worth of fuel but left without paying (stock image)

Highway patrol officers spotted the 12-year-old driving at Broken Hill about 11am on Saturday (stock image)

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.

The boy's attempt to drive to Perth started after 11am on Friday when he took off from the family home in Kendall (pictured), near Port Macquarie

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.'