Carey met with representatives of Dublin-based charity Crosscare last week and was informed about the dangers of BZP, a substance found in many herbal ecstasy pills, which can cause seizures, dilated pupils, irregular heart beat, fainting and impotence if excessively used.

Carey said he was aware of the numerous side-effects attached to the drug and confirmed that gardai were also investigating a number of complaints: "Users of BZP have reported a range of adverse reactions such as vomiting, headache, palpitations, poor appetite, stomach pains, nausea, anxiety, insomnia, strange thoughts, mood swings, confusion and irritability, " he said.

"From a garda perspective, any complaints that the gardai receive are investigated and where offences are identified prosecutions will be mounted. I am aware that a number of prosecutions have already been instigated in this regard."

Michael McDonagh, of Crosscare, said one person died in New Zealand recently after taking herbal ecstasy and a few people had to be hospitalised in the UK after consuming it.

"BZP pills are called herbal ecstasy, pep pills, super E and speed balls and are for sale in some health shops. We would be concerned that someone may soon be hospitalised after suffering adverse effects from taking it, " he said.