One in three Oxfordshire shops targeted in a sting operation were caught selling alcohol to underage teenagers.

Volunteers aged between 13 and 15 tested 25 shops, with youngsters in eight of those being sold alcopops and lager.

Trading standards officers and police issued shop assistants at all eight stores with £80 fines.

Oxfordshire Trading Standards department head Nigel Strick branded the results "worrying and disappointing".

Shops which sold alcohol to the teenagers were JK News, Grandpont, Oxford; Costcutter, Rose Hill, Oxford; Rose Hill News, Rose Hill, Oxford; Londis, Headington, Oxford; Londis, Sutton Courtenay; The Local (formerly Threshers), Jericho, Oxford; Budgens, Peachcroft, Abingdon; Co-op, Longelandes Way, Banbury.

Mr Strick said: "Several weeks ago we publicised the new zero tolerance approach we are taking to prevent sales of alcohol to under 18s.

"That means if alcohol is sold to someone under 18, the seller faces an immediate penalty."

Most of the stores were apologetic last night.

Anwar Dogar, owner of Costcutter in Rose Hill, Oxford, said: "I was not at the shop when this happened. My wife was working and she can't speak good English. I've been struggling to find staff.

"We have got a strict policy on alcohol sales, we do not sell to under 18s. My wife asked them for ID, but they just said they were 18. It won't happen again."

Mushahid Syed, of Rose Hill News, said: "Stupidly, I didn't ask them for ID. Usually I would but it was really busy in the shop that day and Iwas feeling unwell so I didn't think to ask for ID. I will do from now on."

Adrian Barradell, spokesman for the Co-op's Banbury store, said: "This was a regrettable and unusual mistake by a Co-op store.

"We have a detailed training programme and refusal log for this issue. Normally, no alcohol would be sold to an individual who looks under 21 unless they have ID."

Steve Rees, of Londis in Sutton Courtenay, said: "I have shown Trading Standards all the procedures we have in place to prevent selling alcohol to under 18s. We take stringent steps to make sure we do not, but in this case my assistant made a mistake.

"I have looked at the video of the incident and the girl did look old for her age."

At the Londis store in Headington, Oxford, an assistant, who refused to give his name, said: "We usually check for ID. It was just a mistake made by the assistant."

The manager of Budgens in Abingdon referred us to the store's head office, which said: "We were extremely concerned to hear that a member of staff at our store had sold alcohol to an underage person.

"Only last week all staff at the store had been formally rebriefed on the disciplines.

"Budgens fully supports the tough stance being taken on the serving of alcohol to underage persons."

The manager of The Local in Walton Street, Jericho, Oxford, referred us to head office which did not return our call before going to press.

No-one was available for comment at JK News, Abingdon Road, Oxford.