Illicit prescription drugs that can cause severe side effects if taken in the wrong dose are being sold to children on the streets of a major British city for 50 pence (NZ$1).
Mano 10, a type of benzodiazepine which is used to treat anxiety, depression and alcoholism, is being blamed by police for an upsurge in criminality in parts of Hull.
Officers have found users of the little blue pills, known as "Blue Boy", as young as 15 and fear that the "pocket-money" drug could appear in other parts of the country because of its ready availability over the internet.
Its use has already been reported in Ireland where it was described during a court case in August as being "widely available" on the streets.
Users in Humberside have compared the effects of the pill to taking heroin and amphetamines, and drugs groups fear the tablets could be adulterated with other substances.
At least three people have been admitted to hospital after taking the drugs. Two collapsed in police custody and began foaming at the mouth. A third had to be sectioned under the Mental Health Act.
Sergeant Mark Peasgood, of Humberside Police, said youngsters, unaware of the consequences, were taking large quantities of the drug.
In one instance, a user claimed to have taken 60 of the tablets, which are believed to be based on a legal 10mg prescription drug made by an Indian pharmaceutical company and produced in Thailand.
"The effects it has been described as giving are an instant hit and then you get a downer. You forget about everything and during this time people are taking more; people that might cause anti-social behaviour.
"When they have taken this tablet, they lose their senses completely and commit more serious crimes such as burglary," he said.
"It is going to progress from Hull to different parts of the country," he added.
Peta Godney of Compass, a charity that helps young people with drug and alcohol problems, said outreach workers in the city were aware of the presence of Mano 10 which if not prescribed by a doctor is an illegal class C substance, alongside such "party" drugs as gamma hydroxybutyrate (GHB) and ketamine.
"The main danger with the drug is that we just don't know what's in it - it could contain anything. If it does have a type of benzo in it, it suppresses the respiratory system, which means you are in danger of stopping breathing," she said.
Humberside police have made an arrest in connection with the investigation into Mano 10 and a man is currently on police bail pending further inquiries. There is mounting concern over the safety of online drugs which can be bulked out with adulterants such as brick dust and talcum powder.
Last year, police and customs officials seized £8.2m of suspected drugs being sold over the internet. Among the most popular products are slimming pills and anti-tiredness medication. Scotland Yard has shut down 13,000 illegal pharmacy websites, some of which are operated from Russia, India and China.
Last summer, the Scottish government issued a warning about the anxiety drug phenazepam, which was being bought online in place of diazepam, after one user of it in Aberdeen claimed to have nearly died.