According to Greg Murton, from Canterbury's police's Criminal Investigation Branch, the drug is more than three times stronger than MDMA.
"Hence, if N-Ethylpentylone is mistaken for MDMA/ecstasy, the user will be taking three times the 'prescribed' dosage, posing a danger to themselves."
N-Ethylpentylone has been directly attributed to patients' deaths overseas.
Murton said the importers and manufacturers of those type of drugs typically had "no scruples" about what goes into them.
"Dealers have no idea of the potency of the drugs they are supplying, nor what is contained within them, or simply do not care," he said.
He warned users put themselves at risk of serious harm or death by buying party pills, MDMA or any type of synthetic drug.