LAVAL, Que. - Authorities near Montreal are sounding the alarm over the discovery of the deadly opioid carfentanil.

Laval police say it's the first time they've seen carfentanil blotting stamps on their territory.

The paper stamps, soaked in a synthetic opiate, are about 100 times stronger than fentanyl and 10,000 times more powerful than morphine.

The director of the local health agency says the drug is very dangerous and that even a small dose can lead to death.

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.

Dr. Jean-Pierre Trepanier says all opiates can lead to respiratory problems, which cause the user to stop breathing.