POLICE went undercover into Chesterfield pubs - and found less than a quarter were selling alcohol to people under the age of 18.
Derbyshire police and trading standards officers carried out the joint action with the help of young volunteers posing as customers.
The youngsters visited 13 premises in Chesterfield town centre and attempted to buy alcohol. They were served alcohol in three.
Inspector Steve Ball said: “We take the issue of selling alcohol to under-18s seriously and the net is closing in on irresponsible premises who continue to flout the law.
“Underage drinking is a major cause of anti-social behaviour and also poses a risk to the youngsters’ health.”
Staff caught selling alcohol to youngsters were issued with an £80 fine and the venues will be investigated.