An elderly couple told police in the English town of Bedford they unknowingly purchased a cannabis plant at a car boot sale, believing it to be a generic green shrub.

Finding it more funny than felonious, Bedford Police tweeted a photo of the plant in question, noting it had been "tended carefully" and was the "biggest cannabis plant we had seen."

The cannabis was subsequently seized and a spokesperson said it slated to be destroyed. No charges will be brought against the inadvertent pot farmers.

[photo via @BedfordLPT]