There is concern that teenagers can but alcoholic drinks

An investigation by BBC Wales' Week In, Week Out programme, has found that binge-drinking is commonplace among children as young as 13 and 14 in Wales.

And the programme, broadcast at 2235 GMT on Tuesday, reveals new research indicating that doctors are seeing symptoms of chronic alcohol abuse in younger patients than ever before.

Trading standards officers carried out undercover investigations using teenage volunteers in Wales last autumn.

They could be selling what is, in all essence, a beginner's drug, to kids, and they have to take that responsibility very seriously Dave Holland, Cardiff council

The investigations showed that in some parts of Wales, one in two off licences was selling alcohol to under-18s.

Overall, trading standards officers found that one in three teenagers was able to buy alcohol in local stores.

In Cardiff, there was a 10% increase in the number of off-licences selling to under-18s during a further series of 50 visits on shops in the city last month to which Week In Week Out was given access.

Overall, 39% of stores targeted during the operation sold alcohol to the teenage volunteers sent in undercover.

Some licensees now face prosecution.

Dave Holland of Cardiff council is concerned at the findings

Dave Holland, operational manager for consumer protection at Cardiff County Council, said: "They have a drug in their hands.

"They could be selling what is, in all essence, a beginner's drug, to kids, and they have to take that responsibility very seriously.

"If they don't, they are going to reap the consequences of that in a few years."

A recent survey revealed that Welsh teenagers drink more than their counterparts in England and most of Europe.

Week In Week Out speaks to teenage drinkers and their parents about the impact their habit is having on their lives, and goes out on the beat with police as they tackle young drinkers on the streets.