People are being asked to help police bust cannabis farms by sniffing them out.
Cannabis gives off a different smell when it is growing than when it is being smoked.
More than seven hundred farms have been raided in the West Midlands in the past two years.
Today the Crimestoppers charity has been out and about with a scratch and sniff card impregnated with the smell of a cannabis plant to help people spot if someone's cultivating near them.
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