One man was dead and two others were in cardiac arrest when paramedics called police to a home in Vancouver last Sunday.
A 24-year-old man, who was found unresponsive in the home, died.
The cause of the man's death has yet to be established, but spokesman Const. Brian Montague said police seized oxycodone and ecstasy from the home.
He said lab tests are back and confirm the oxycodone, wasn't oxycodone. It was fentanyl.
Montague said police suspect the man died of a drug overdose, but his two friends survived.
In October, Vancouver police issued a warning about fentanyl masquerading as heroin. It caused more than 30 overdoses and one death that month.
John Carsley, Vancouver's medical health officer, warns fentanyl can show up in a variety of ways.
"No matter what the appearance of the drug being sold or what you are told it is," said Carsley, "there is never any guarantee you are buying what you think you are buying. It may be stronger, contaminated or contain a completely different substance.”
Carsley said police and health officials warn against the use of street drugs, but recommend those who do use, not consume them while alone, and be alert to the symptoms of an overdose.
Where possible, police and health officials recommend the use of the supervised injection site, Insite, which is staffed by medical personnel who can intervene in the event of a drug overdose.