FREDERICTON -- New Brunswick's acting chief medical officer of health is warning the public about a deadly drug that's far more powerful than fentanyl.

Dr. Jennifer Russell said Friday the emergence of carfentanil in New Brunswick's illegal drug market is a major concern.

A toxicology report revealed carfentanil was found in the system of an individual who died recently in southern New Brunswick, she said.

Russell said that because of privacy concerns and an ongoing investigation, she can't reveal exactly where and when that death occurred.

"This is a general announcement for the entire province. In other jurisdictions where it has arrived we know that it's important to let people know, especially vulnerable and high-risk groups," she said at a news conference in Fredericton.

Russell said carfentanil is a synthetic opioid about 100 times more powerful than fentanyl.

It only takes an amount equivalent to a grain of salt or two milligrams of carfentanil powder to be lethal through inhalation, ingestion or absorption through the skin.

The drug can be mixed with other drugs and cannot be detected unless tested in a laboratory.

Russell said what makes it so dangerous is that people don't know it's being included in other street drugs.

She said New Brunswick is learning from other provinces on how to address the opioid issue, especially from British Columbia, which declared a public health emergency in 2016 because of the number of fentanyl overdoses.

"We continue to learn from that province. We continue to learn from Alberta and Ontario. We've done all the things that we needed to do in the shorter term. We're looking at medium- to long-term approaches also," Russell said.

New Brunswick had 25 deaths due to drugs between Jan. 1 and June 30 of this year, and Russell said 17 of those were related to opioids.

The RCMP have said dealing with the trafficking of fentanyl and carfentanil is a top priority.

In October, police in southern Ontario seized 42 kilograms of carfentanil, saying it's believed to be the largest seizure of the drug in the country.

-- By Kevin Bissett in Moncton.