Officials from the Nelson Fentanyl Task force are warning that carfentanil has been found in a drug sample from Castlegar.
The sample, taken March 22, tested positive for the deadly drug.
This is the first time carfentanil has been detected in Castlegar.
The test was done by the drug analysis service laboratories, regulatory operations and enforcement branch of Health Canada.
Officials are warning drug users to never use drugs alone, and always carry Naloxone. Consider using the overdose prevention site at ANKORS in Nelson.
Last month Interior Health issued a warning about carfentanil in the drug supply.
Carfentanil may have been the cause of 19 drug-related overdose deaths in B.C. in March.
Carfentanil is a synthetic opioid normally used as a sedative for large animals. It is similar to fentanyl, but is more concentrated and can be 100 times more toxic to humans, to the point where ingesting one or two grains can be fatal.