Forensic scientists detected 27 new recreational drugs in Ireland last year which are manufactured as cheaper alternatives to narcotics such as cocaine and cannabis.

Stopping the spread of the laboratory-made substances – classed as “New Psychoactive Substances” (NPS) or head shop drugs – was proving difficult as they were largely being bought online and were not being detected by gardaí and customs officials, said Forensic Science Ireland (FSI).

Most of the new drugs detected were synthetic forms of cannabis with one of the most popular versions going by the street name “Spice”.

However, the 27 new substances detected as part of a Europe-wide monitoring initiative fell into five categories: Benzodiazepines, Cathinone, Tryptamines, NBOMes and Fentanyls. At total of 98 new substances were detected across Europe in 2015.

“It’s a growing phenomenon,” a spokeswoman for FSI said.

‘Stock and trade’

She added that the “stock and trade” of the FSI drugs division – which is responsible for classifying seized drugs and assessing their purity – had traditionally been “the big ones” such as cannabis, cocaine, heroin and ecstasy.

“The difference is those drugs show up on the street and are confiscated by the gardaí and brought into the FSI but most of these new drugs come from online sales,” the spokeswoman added.

Much of the supply of head-shop drugs dried up in 2010 when the government introduced legislation banning their sale.

However, FSI said the drugs were being imported into the country in increasingly large amounts.

“They’re manufactured in eastern Europe and China and then they make their way through customs into people’s homes,” the spokeswoman added. “So there’s just a different distribution of them. They’re probably underrepresented in the stats because guards aren’t picking them up on the street.”

Among the drugs detected was 25I-NBOMe, more commonly known as N-Bomb, a psychedelic said to be responsible for the death of an 18-year-old in Cork city last year.

Scientists also encountered several types of fentanyl drugs which have been linked to several overdose deaths.