A purple substance recently seized by Waterloo Regional Police could contain the dangerous drug fentanyl.

A public alert about the substance was issued Tuesday.

According to the Waterloo Region Integrated Drug Strategy organization, the substance was seized by police last week. Little is known about it other than that it is purple and appears similar to the Play-Doh children’s toy.

The substance has been sent for testing. Authorities say it may be similar to a mix of fentanyl and heroin which has been linked to multiple overdoses in the Hamilton area.

Public health authorities say all drug users should remember never to take drugs while alone, and to start with a small amount of any substance.