Several kilograms of a synthetic cannabis known as "Venom" were seized from two properties in Perth's southern suburbs yesterday.
No one has been charged over the drugs but the investigation is continuing.
Police are warning that although products such as Venom are often marketed as legal highs, all synthetic cannabis products are illegal to possess or sell in WA.
The ChemCentre has identified the active ingredients in Venom as the synthetic cannabinoids AM2201 and XLR-11, which can cause elevated heart rate, elevated blood pressure, anxiety and hallucinations, seizures and long lasting perception disorders.
Police are advising anyone who has Venom to destroy it immediately.
Anyone with information about the manufacture, importation or distribution of any drugs is asked to contact Crime Stoppers on 1800 333 000.