Cocaine sold in Ireland is most commonly cut down with a veterinary drug to treat parasitic worm infections, according to a new report on illicit drug use by Forensic Science Ireland.

Levamisole, a veterinary medication used to treat parasitic worm infections, is thought to be added during cocaine production to increase its effects.

Cocaine seized in Ireland last year was commonly adulterated with levamisole, benzocaine, lignocaine, caffeine, and phenacetin.

Benzocaine and lignocaine, which is also known as lidocaine, are local anaesthetics commonly used by dentists.

Phenacetin is a painkiller which has been banned in a number of countries as overuse has been linked to certain cancers.

Meanwhile, the average purity of amphetamine seizures analysed in 2015 was 9.2%.

Street level cocaine had an average purity of 28% in Dublin and 19% outside Dublin, while street level heroin was 33% in Dublin and 35% outside Dublin.

The purity of bulk cocaine and bulk heroin seizures was 40%.

Across Europe, amphetamine seizures last year were generally 9-19% pure, with cocaine typically found to have purity levels of 33-50% and heroin generally 13-23%.

Forensic Science Ireland analyses illicit drugs seized by An Garda Síochána and the Customs Service and issues Certificates of Analysis for court purposes.

Common adulterants found in heroin were caffeine and paracetamol. The most common adulterant found in amphetamine is caffeine.

FSI’s Director of Chemical Services this afternoon said people really do not know what they are getting when they buy drugs on the street.

Speaking on RTÉ’s News At One, Dr Tom Hannigan said many of the drugs sold may not even contain the substance people think they are buying.

"Basically when somebody buys something on the street, they really do not know what they're getting. They may not even be getting the drug that they think they're getting, so that's the danger we're warning against."