Keith Hellawell says some state schools already test for drugs

The former West Yorkshire Police chief constable made the call after a survey showed almost half of children had been offered drugs in schools.

In the Bliss magazine survey, 44% said they had been approached at school - the figure rises to 60% in Yorkshire.

Mr Hellawell said this strengthened the case for drug testing, which he claimed is already under way in some areas.

"I'm certain it is likely to happen - a lot of schools in America already do this," he told BBC Radio Leeds.

"My understanding is there are a number of private schools that have done it for some time, but there are also a number of state schools doing it.

"We have now reached the time when we ought to have drug testing in schools and it ought to be part of their [drug] education strategy.

We are trying to put pressure on schools to cure the ills of society Sue Sale, former NAHT president

The former police chief added that children asked about the issue "felt it would help them resist pressures they are under to get involved".

Andrew Marshall, whose 12-year-old daughter attends Leeds High School, said the prospect of drugs in schools worried him as a parent.

"I'm 36 and when I was at school it was unheard of - so it is a worry when you hear they are available.

"I think if the school had a drug problem I would welcome some kind of compulsory testing."

But Sue Sale, a former president of the National Association of Head Teachers (NAHT), said she was "deeply concerned" about the practicalities of implementing tests.

"I think we need to remember that drugs is a community issue - not just one for schools.

"We are trying to put pressure on schools to cure the ills of society.

"There are some pockets of the country where it is an issue, but the whole community has to deal with it - including parents."