An 11-year-old girl has received hospital treatment after collapsing from the effects of smoking Heroin.

The Primary 7 pupil, who cannot be named, appeared to fall asleep during lessons last week. Teachers suspected that she had unwittingly ingested drugs and she was taken to Yorkhill Children's Hospital, in Glasgow.

But she later told doctors that she had been buying £10 bags of heroin, a class A drug, from a dealer near the city's Pollok shopping centre for eight weeks.

Strathclyde police said an investigation had been launched. The news prompted condemnation from local politicians and anti-drugs campaigners.

"Clearly it is a great worry to find that any primary school child is using hard drugs," said Ian Davidson, Labour MP for Glasgow South West.

"We need to identify whether this is a particular issue to this family or, more worryingly, if this is the tip of the iceberg in terms of this sort of drug use among classmates.

"Unfortunately there are large numbers of locations where drugs can quite freely be purchased, both in Pollok and elsewhere in the city.

"And we've got, perhaps, to concentrate more on sweeping up a lot of the low level dealers rather than constantly trying to catch the 'Mr Bigs' because it is the low-level dealers who cause the annoyance and irritation and fuel the use of drugs."

Scotland Against Drugs has trained thousands of teachers and school heads to deal with children and parents who use drugs.

Its director, Alistair Ramsay, said: "Thankfully, incidents like this are very rare but when they occur they are truly shocking."

But Cllr Gaille McCann claimed that the case was "not an isolated incident".

She said: "This is the harsh reality of the drug problem today and it must not just become a seven-day story but instead act as a wake-up call to us all, particularly the policy-makers in their ivory towers."

"They must look at the whole issue and the policies in place, from prevention and treatment to enforcement, because they have clearly failed this wee girl."

Helen Hunter, the assistant director of Children 1st, a Scottish child welfare charity, said: "This is frightening. Clearly the people cruel enough to sell heroin to an 11-year-old girl need to be stopped. Just as importantly, however, you have to ask how an 11-year-old girl knew about buying and using drugs."