It's taken just over a month for the first new form of Kronic - the most popular brand of synthetic cannabis - to make its way back onto the shelves after the substance was outlawed in WA.

And police are already working with the state government to test the ingredients in the product, reportedly branded "Kronic Black Label", to determine whether it needs to be outlawed.

A photo posted on ABC Perth's Facebook page purportedly of a shop selling a new form of synthetic cannabis.

Police confirmed this morning they were investigating reports that a store in Perth's northern suburbs was stocking the product.

The Auckland-based manufacturing company believed to be importing the product into Australia describes the product on its website a "the height of innovation" and that the new Kronic was developed "in response to demand".