The county council tested retailers in the Matlock, Buxton and Bakewell areas with the volunteers going into stores.

Ten out of 22 shops and garages tested sold the girls alcohol. Now trading standards officials say they may prosecute the retailers.

"It's disappointing that so many sales of alcohol were made to children," said county councillor Walter Burrows.

"We work with traders throughout the year to stop underage sales, so ignorance is no defence.

"The law is there to prevent injury and harm and the young volunteers used were three and four years younger than the age at which alcohol can legally be sold. "