The deadly synthetic opioid Fentanyl is now circulating in New Zealand.
In Wairarapa, twelve people overdosed on the drug at the weekend and were hospitalised.
It had been sold to them as cocaine.
Fentanyl is believed to be the main driver behind a significant increase in drug overdose deaths in the United States.
The US National Institute of Drug Abuse's science policy branch chief Dr Emily Einstein spoke to Susie Ferguson.
