A member of staff at Bristol retailer Mohammad Aziz's
Staple Hill store sold four large bottles of cider to the youngster in a sting operation organised by the Daily Mirror.
Mohammad admitted that the alcohol was indeed sold, but said he had no idea why the store's normal procedures were not followed.
He told Convenience Store: "I've apologised and would again like to say how sorry I am for what has happened. The member of staff involved has also said how sorry he is and he has had to have a number of days off ill because he is so upset by the incident."
Mohammad said that he had never failed any test purchases in the past and has a good relationship with local police. He said in his defence that the member of staff had been very busy, but said he recognised this was not an excuse.
He added: "We are very strict people and we always check for ID. I don't know how this happened and neither does the member of staff. The police know we are very strict on selling age-restricted goods and have never had a problem with us. I do admit a genuine mistake was made. I don't know what more I can say."