Vancouver Police say they have detected the deadly opioid carfentanil for the first time in a Vancouver drug seizure.

Health Canada has confirmed the presence of carfentanil in drugs that were seized in the Downtown Eastside on Sept. 20.

Police confiscated several grams of what they believed to be heroin from a man in the north lane of Powell Steet and Heatley Avenue after reports that the man was carrying a firearm.

Carfentanil resembles table salt but is 100 times more potent than fentanyl. (Canada Border Services)

Carfentanil is 100 times more potent than fentanyl and is used to tranquillize elephants and other large animals. It can be fatal to humans in an amount of 20 micrograms, which is less than a grain of salt.

"We've seen a drastic increase in opioid drug overdoses in the last few years mostly due to the presence of fentanyl," said S/Sgt. Randy Fincham of the VPD. "And with the latest detection of carfentanil, it is certainly alarming."

Fincham says the sample in question was heroin that had been cut with carfentanil.

He says opioid drug users and anyone associated with them need to be aware of the signs of overdose.

Linked to 2 Alberta deaths

Sgt. Brian Montague said the existence of carfentanil is concerning because the coroner's service has already reported 622 illicit-drug deaths in British Columbia between January and October, with fentanyl involved in 60 per cent of them.

"In the last few days we've had more deaths in the Vancouver area than we would see in about a month," Montague said, adding fentanyl is suspected.

Barb McLintock, a spokeswoman for the coroner's service, said it's too early to say if the deaths involve illicit drugs.

Alberta's medical examiner reported last month that carfentanil was detected in the bodies of two men in their 30s.

Mounties in that province have said they seized a cache of carfentanil last summer and that it had the potential to create 50 million lethal doses.

With files from The Canadian Press