Cannabis is getting harder to find in small towns where meth can now be more easily obtained.

That's one of the findings of a Massey University study which has compared the availability of both illicit drugs.

Researcher Chris Wilkins says large amounts of P is making its way into the regions.

He told Mike Hosking anecdotal evidence suggests many forms of cannabis are becoming harder to get hold of.

"Sometimes they go to their dealer [and] they don't have enough cannabis or they don't have the type they want. Compared to methamphetamine users who say this is always available."

LISTEN TO CHRIS WILKINS TALK WITH MIKE HOSKING ABOVE