05/22/2013 11:50 EDT | Updated 07/22/2013 05:12 EDT

Fentanyl-related deaths spark warning in Prince George

Mounties in Prince George, B.C., are warning drug users about the powerful prescription opiate fentanyl which has turned up on the city’s streets.

Police say two deaths in the past six months appear to have been caused by fentanyl. Both the men who died were known heroin users.

Cpl. Craig Douglass says the narcotic, which looks like heroin but is much more potent, isn't typically found on the streets.

"So if somebody who is a regular user of heroin, they know the dose that their body is able to sustain, essentially if they put that same dose of fentanyl in their system, not knowing that it's fentanyl, it could be fatal,” he said.

Police are now investigating the possibility it's being mixed in with or sold as other drugs.

Dr. Kelly Barnard with the B.C. Coroners Service says fentanyl is typically used to treat severe pain for illnesses like cancer.

“It absolutely is a dangerous substance and should not be used for anything other than what it's prescribed, which is under the care of a physician for use in extreme pain,” she said.

“It's safe when used as prescribed, and under the care of a physician, but any other use is very dangerous."

Barnard says the B.C. Coroners Service has found an increase in fentanyl-related deaths across the province over the past several months.