Winnipeg police have issued a warning about experimental drug use, after two men were found in a car, dead from a possible overdose.

Investigators found drug paraphernalia on the bodies of the two individuals, ages 27 and 35, who were discovered in a vehicle near an elementary school on Monday. Police say they are now looking into the possibility that fentanyl or carfentanil may have played a role in the deaths.

Fentanyl is a potent opioid that can be synthetically produced and added to existing hard drugs, like cocaine or heroin, to achieve an additional high. However, the drug is extremely powerful, and can be dangerous even in small amounts. It has a potency 100 times that of the painkiller morphine. Carfentanil is even more powerful, according to the U.S. Drug Enforcement Agency, at 100 times stronger than fentanyl or 10,000 times stronger than morphine.

Const. Jason Michalyshen said it was a "possibility" that one of those drugs may have been involved. He warned that fentanyl and carfentanil can be deadly, especially when combined with other substances.

Doctor Ginette Poulin, medical director at the Addictions Foundation of Manitoba, said using experimental drugs can be "like Russian roulette," because users can't be sure of the amount of fentanyl added to a dealer's product.

Const. Michalyshen echoed those sentiments at a news conference. "There is that risk that there may be something present there, whether it be fentanyl or otherwise. They're putting their life at risk, and it's a gamble."

With files from CTV Winnipeg