Halifax police are warning of a dangerous combination of drugs that were seized from an impaired driver during a traffic stop.

It happened in April around 3:30 a.m. near Sea King Drive and Albro Lake Road.

After a search of the vehicle, officers found an unknown substance described as grey/green in colour and in a grainy powder form.

Health Canada confirmed this week that Metonitazene, a potent synthetic opioid was detected as well as Fentanyl, Caffeine and Dimethlsulphone.

Police say this combination of drugs is dangerous and may put users more at risk of an overdose.

Even handling them can be risky without taking proper precautions.

Police suggest using Naloxone in experiencing an overdose.