Police records have shown a boy aged nine was arrested for drink driving.
The youngster, from Cumbria, was breathalysed and taken into police custody.
But when officers discovered his age they were forced to release him without charge as he was too young to be held accountable for his actions.
Safety campaigners have since demanded action to curb juvenile car crime.
The child, who has not been named, was just one of thousands of under 18s arrested in the north of England over the past two years.
These included four 11-year-olds and a ten-year-old arrested in the Northumbria force area for car theft, and seven 12-year-olds arrested in Cleveland for the same crime.
During the same time period, Durham Police arrested one 12-year-old for aggravated vehicle taking and North Yorkshire Police arrested one ten-year-old for car theft.
These were among 2,467 juveniles arrested for crimes including car theft, aggravated vehicle taking, drink driving and underage driving.
Kath Hartley, of the charity Brake, which campaigns for lower speed limits, demanded road safety education be taught in school.
She told The Sunday Sun in Newcastle: "It is incredibly concerning that young people are risking their own and other people's lives on the road. This must be addressed as a matter of urgency."
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