Up to a fifth of children aged between nine and 11 in parts of the West Midlands drink alcohol, as do more than a quarter 12-13 year olds, a new study has indicated.

The survey, commissioned by Dudley Primary CareTrust , has 17 per cent of nine to 11-year-olds admitting to drinking at least once during the last week - and six per cent of those drinking without their parents knowledge.

Health professionals have called for more research on the scale of underage drinking, to prevent an explosion of drink-related health problems further down the line.

Dudley is one of the only primary care trusts to conduct the two-yearly child lifestyle survey, via its Schools Health Education Programme - which it uses to better direct its health resources.

The on-line survey of 5,480 pupils found that 39 per cent of 14-15 year olds drank, and of those 15 per cent said they drank more than the advised weekly limit for adults.

One of the few other indicators on the issue are records of A&E episodes and hospital admissions - with the latter placing Birmingham and Sandwell near the top of England's underage drinking league.

In the Birmingham local authority area between April 2002 and April 2005 a total of 299 under 18s were admitted onto a hospital ward because of acute alcohol poisoning - more than of them half female.

Birmingham had the 11th highest proportion of under 18s seeking such treatment out of 354 local authority areas, and Sandwell came 13th.

The numbers of teenagers attending A&E because of excess alcohol consumption, and not admitted to a ward, is thought to be much higher - but there are few systems yet in place to capture such data.

But Gavin Rudge, data scientist at West Midlands Accident and Emergency Surveillance Centre, University of Birmingham, was able to obtain figures for City hospital for the last two years.

He found that from 2004 to 2005 72 youngsters aged 16 or under arrived up at A&E because of alcohol intake. The following year, 2005/6 the total had fallen to 47. About five of those were under 13 in each year.

Mr Rudge said the turnaround could be misleading. "The weight of anecdotal evidence suggests that there is a growing problem with alcohol abuse in minors," he said. "It is possible that stricter enforcement of under-age drinking and intensive policing in the city centre may result in younger drinkers staying closer to home, so A&E departments serving more suburban locations may see different and possibly more serious trends."

Deputy regional director of Public Health for the West Midlands, Dr Jammi Rao, said the recorded hospital episodes were likely to be the tip of the iceberg.

"The accident and emergency event is the sharp end of the problem," he said. "For every child who drinks to excess and is carted off to A&E there are clearly many children who have been drinking."

"Not every child drinks to excess - many more are experimenting and drinking.

"The trouble is we don't know how many are involved or what problems it will lead to in the future. Research is needed."

The Maypole youth centre in South Birmingham is piloting a scheme for the Department of Health for the intervention and treatment of teenagers with alcohol problems.

Funding from Comic Relief has recently seen youth alcohol worker installed there, linked up to Birmingham community alcohol service, Aquarius.

Currently there is no system of referrals from GPs to the service, but they are hoping to put one in place.

Youth alcohol worker Lindsay Owen said: "Health services need to commission these surveys to find out what the problem is.

"One of the reasons we've got the money is to develop this work is because no-one knows what the issues are or what the scale is because there is so little data.

"Our hunch, and it's a reasonable one, that young people's career of drinking is starting earlier - drink is cheaper, reasonably accessible and heavily marketed.

"We want to identify the problem, intervene and educate."