LONDON (CNN) -- British police have decided not to press any charges against the elderly couple who had been unknowingly cultivating a huge cannabis plant in their garden.

The plant was seized Monday. The police later posted a picture on Twitter with comments: "Elderly couple bought shrub at car boot sale," adding that it was the "biggest cannabis plant we had seen!!"

The police picture posted on Twitter shows a fully grown shrub with thick foliage in the front garden.

A police spokeswoman told CNN: "The plant was mistakenly bought by the elderly couple. We will not be pressing any charges. We have seized it and will dispose it." She also said that unlike what has been reported in some newspapers there was no "raid."' "The property was not raided," she said.

The police tweet, however, led to many comical reactions including on newspapers sites that carried the story. A Mail Online reader commented: "Don't buy 'pot' plants at car boot sales! Simples."

Cannabis is classified as a Class B drug in Britain under the Misuse of Drugs Act. The maximum penalty for supplying or producing cannabis is 14 years imprisonment and/or unlimited fine.

The cannabis plant has psychoactive compounds with mood and behavior-altering properties. The plant is used both for making recreational drugs and medicine. Organized crime gangs have often used in-house cannabis farms to produce the high-strength "skunk" version of the drug.

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