Pharmacists in the Republic of Ireland have been put on a nationwide alert to report large sales of over-the-counter medicines, which can be used to manufacture a killer drug.
Gardai warned last night that tablets like Sudafed, which are normally taken to cure a common cold, can become key ingredients in homemade crystal meth.
Pharmacies in Dublin, Limerick and Kerry have already reported significant purchases of Sudafed in their premises.
Officers said that users of crystal meth usually die within 18 months and in the meantime suffer from horrendous side effects.
The drug makes users tear their skin off by constant scratching and their teeth rot from the inside out.
A Polish man was arrested for questioning after gardai found a makeshift laboratory during a raid in Tralee last month.
Detectives also recovered a haul of crystal meth, worth around €8,000 on the streets, and a quantity of Sudafed tablets. The man was later released without charge but a file is currently being prepared for the Director of Public Prosecutions. Unusual purchase patterns were also spotted at pharmacies on the southside of Dublin and in Limerick city.
The buyers were either purchasing in large quantities or else groups were making almost daily visits to the shops.
Most of those thought to be involved are eastern Europeans.
Detectives think that some of the homemade manufacturers got the idea from watching the hit US television series, 'Breaking Bad', in which the main character, who is dying from cancer, turns to making crystal meth to create a financial nest egg for his dependants.
Tablets like Sudafed contain pseudoephedrine which can be used in the manufacture of methamphetamine, or crystal meth, which is described as a dangerous and highly addictive drug.
As a result of garda concerns, the Pharmaceutical Society of Ireland circulated its members to advise them to control the location and storage of the medicines and if their suspicions were aroused by the customer's request to use their professional judgment to determine if the medicine was appropriate for the patient.
The pharmacists were told they had the right to refuse the medicine to a customer and also to notify the gardai of their suspicions.
The Irish Pharmacy Union also notified its members of the purchase patterns and the dangers involved.
The Garda National Drugs Unit is spearheading an operation, codenamed Shutdown, to investigate the extent of the use of Sudafed in the manufacture of crystal meth.
Officers say that some homemade manufacturers are using what is known as the 'One Pot Method' in which a two-litre soft drinks bottle is used to mix the tablets with other ingredients such as floor polish and nail varnish remover and then subjected to light heat.
This is also known as the 'shake and bake' system and the crystal meth is extracted from the sludge when it is complete. But if it is not mixed properly, the concoction has the potential to explode and can cause serious injury.
The crystal meth is manufactured on an industrial scale on the US-Mexican border and the laboratories are not usually found until they blow up.
Gardai said an analysis was carried out five years ago to establish if the drugs could become a major threat on the streets of Europe but concluded that it was not likely.
Hardened users indulge in a three-day binge, known on the streets as tweaking, and this leaves them lifeless after the initial rush of euphoria.