A girl who needed hospital treatment after consuming vodka was just nine years old, according to police who are growing concerned about pre-teens drinking.
Durham Police are also investigating how a 12-year-old required accident and emergency treatment over three consecutive weekends for alcohol-related injuries.
Alcohol campaigners blamed "pocket-money prices" for the extent of the problem, which police warned left children at risk of sexual exploitation by adults.
The nine-year-old girl, who lives near Consett, County Durham, was found to be in a dazed state after drinking vodka with two friends who were about the same age. Her parents called an ambulance.
Medics alerted the police, who spoke to the family last month.
The shocking incident was not unusual, with officers blaming peer pressure for an increase in drinking among the very young.
Officers in nearby Stanley have begun an investigation into how a 12-year-old needed hospital treatment for injuries suffered after drinking over three weekends.
Sergeant David Clarke said: "Under-age drinking is a severe problem with younger children drinking through peer pressure. It is a growing concern."
Not only did it damage their health, it put them at risk of sexual abuse, the officer said.
"There is a very strong link between alcohol and sexual predators. It could just be people who find them in such a state or people who supply them with alcohol in return for sexual favours. It is used as a commodity," he said.
Colin Shevills, director of Balance at the North East Alcohol Office, said: "Here in the North East we have the highest rate of under-18 alcohol=specific hospital admissions and the highest rate of under-18s in alcohol treatment.
"Clearly, pocket-money prices, widespread availability and heavy marketing have established drinking as a social norm and it is having a harmful effect."