Gangs in Ireland are selling cocaine mixed with drugs to deworm cattle, anaesthetics and cancer-causing painkillers, research has found.

Analysis by State forensic experts found street seizures of the drug had purity levels as low as 19% outside Dublin and 28% inside the capital compared with 33%-50% purity across the rest of Europe.

Forensic Science Ireland, based at Garda headquarters, revealed that dealers and trafficking gangs were bulking up cocaine hauls with agents like levamisole, which is used by vets to treat parastic worms but is added to cocaine to improve its potency.

Other additives include benzocaine and lignocaine, which are local anaesthetics used in dentistry, caffeine and phenacetin, a painkiller banned in a number of countries as overuse was linked to certain cancers, the agency said.

The laboratory’s examination of drugs seizures made last year by the Garda and Customs also showed that the average purity of amphetamine was 9.2%.

Heroin on the streets of Dublin had a purity of about 33%, and 35% outside the city.

Forensic Science Ireland said bulk cocaine and heroin seizures in Ireland had purity levels of 40%.

It said it mainly dealt with cannabis, heroin, cocaine, benzodiazepines and MDMA, or pure ecstasy, last year and that it will deal with about 8,000 seizures this year.