A former Bradford police chief is offering testing kits to parents as the latest weapon in the battle against Drugs.

But his ideas have been criticised by some drug experts in the city who say they could irreparably damage relations between parents and their children.

The controversial oral swab kit means samples can be taken from children in the home and analysed for drugs such as heroin, cocaine, ecstasy and cannabis.

Drugs expert Les Vasey, formerly divisional commander of Bradford Central Police, has set up a company to market the product to employers. He intends to sell the kits to parents and hopes local schools will also take up the tests.

Mr Vasey, also a former co-ordinator of Bradford's Drug Action Team, said he had spent two years researching the idea and was becoming concerned about the number of young heroin addicts in Bradford.

He said: "Up to five years ago, we were talking about 18-year-olds progressing from cannabis to other drugs, but adolescents are starting on heroin because of its cheapness and availability.

"We want to answer our critics by saying it's better for the parents to find out what their kids are up to before there's a police knock at the door saying they are in a cell or dead from a heroin overdose."

Shipley-based Modern Health Systems will offer a package of family counselling and advice before selling the tests, which cost from £10. The home kit includes a spatula to take a sample from inside the mouth, which is then sent in preservative fluid to a laboratory to be analysed.

Youngsters will be referred to local services if tests prove positive.

Mr Vasey said the radical technology was widely used in the United States, but only available over the Internet in the UK.

"We don't think that's responsible," he said. "We will ensure they have the necessary advice. We believe in the philosophy of parents testing their kids, but only with their consent.

"I think most kids want to reassure their parents that they're not using drugs. There will be another group who are using drugs recreationally who may be less willing. But we discovered in our research that a number of older addicts are in recovery and trying to establish trust in relationships to come home. One way they can establish that trust is to prove they are clean and staying clean - they can offer to be regularly tested.

"In my experience, every addict wants to come off drugs because it's destroying their life."

But a spokesman for DrugScope, an expert body which advises professionals and the public on drugs issues, described the kits as "crude".

"They might not necessarily identify someone with a serious drug problem," she said. "They introduce an element of suspicion into children and parent relationships and if drugs are involved, it's particularly important there is a good relationship between the two."

Bradford GP and clinical lead on drug and alcohol misuse at Bradford City Primary Care Trust, Dr Martin Taylor, agreed the test could harm family relationships. "It's like a parent reading a diary," he said. "It's a breach of trust between the parent and child - it sets a watershed which may affect their relationship in the future."

Yvonne Oliver, of Buttershaw's Ripple drugs project and mum of two heroin addicts, said oral swab tests were more reliable than urine tests as they could not be easily cheated.

But she added: "If you found out your kids were on heroin, then what? There's nothing wrong with this except it's not a good idea to be telling parents that the solution to their problem is finding out. The solution is not being a vigilante."

Hillary Temple, deputy principal of Dixons CTC and chairman of the Bradford Drugs Prevention in Schools initiative, said she would not support the test.

"We wouldn't test for drugs in schools because that's reactive, not proactive," she said. "We need to educate youngsters so that they have all the information to make the right, well-informed choices so they are not subjected to peer pressure."

Meanwhile, the Government has urged revellers to use its National Drugs Helpline to find out about the damaging long-term affects of drugs before being tempted to take them at New Year's Eve parties. The helpline is open 24 hours a day on 0800 776600.