Toronto police’s drug squad are warning the public about an opioid they believe to be forty times more potent than heroin, which has killed scores of drug users in Vancouver this year.

Insp. Howie Page says fentanyl, a prescription opiate used to treat severe chronic pain, is being abused and also inserted into other more commonly known street drugs, leading to potentially lethal overdoses among users.

"Vancouver police are investigating numerous deaths of users who consume fentanyl believing it was a different drug altogether," Page said, adding that in several cases users believed they were taking oxycodone.

Officials in British Columbia say 55 deaths in the province can be attributed to fentanyl use so far this year,

The drug can be consumed as a pill, a skin patch, or crushed and snorted. The skin patch releases the drug slowly over a period of two or three days.

But Page said some already used patches are stolen out of garbage bins and chewed by drug users.

"Sucking the drug out of the patch can make the drug lethal."

A study by the Canadian Centre on Substance Abuse linked 655 deaths between 2009 and 2014 to using fentanyl.

Page said there have been few instances of fentanyl use inside Toronto, but many cases have been reported in the GTA and northern Ontario. Toronto police fear the drug may increase in popularity in the future.

Last week, police say about 20 patches were taken from a parked car in the area of Yonge Street and Finch Avenue. Page said the car belonged to a person who had a legal prescription for them. The patches are still outstanding.

Unused prescription fentanyl patches can sell for as much as $200 per patch.

Anyone with information about fentanyl trafficking is asked to contact police at 416-808-6100.