THE PURITY of cocaine on sale on the streets is set to decrease dramatically after the government ban on legal high products.

Cocaine purity had increased in recent months as drug dealers attempted to lure people away from buying legal highs at head shops. But sources working in drug enforcement now expect the purity of cocaine to decrease.

Drug dealers often cut cocaine with lignocaine, a heart medication, to maximise their profits. However, by cutting the class-A drug with lignocaine, it can intensify the effects of cocaine on the heart, causing sudden death in some cases.

A senior source said intelligence suggested that many drug dealers had stopped cutting cocaine with lignocaine in a bid to win back some of its customers, who turned in their droves to buying legal highs, which are far cheaper.

Dealers are expected to return to once more reducing the quality of cocaine by cutting it with lignocaine. Criminals are also now planning to import large quantities of the newly outlawed drugs to sell on the streets, according to a source.

At an inquest at Dublin City Coroner's Court last month, coroner Brian Farrell described the combination of cocaine and lignocaine as "very dangerous". He made his comments at an inquest into the death of a mother and her unborn child who both died last year after she took cocaine cut with lignocaine.

Lisa Hart (32) and her unborn son, Elton Hart, died in March of last year after the six-month pregnant mother collapsed at home.

"We are having inquests regularly where cocaine is the cause of death cut with lignocaine. We have been in touch with the gardaí about it. We have very grave concerns about it," coroner Dr Farrell said at the inquest.

Some of the country's 102 head shops closed down on Tuesday after the government launched a crackdown on their products. An array of legal highs were banned with immediate effect on Tuesday.