As drug raid targets go, they were hardly the usual suspects.

Chris and Anne Vincent, a respectable couple in their late fifties, answered the door of their village home to find police demanding access to their garden.

Neighbours had reported how streams of local teenagers had been knocking on the couple’s door asking to buy marijuana.

And police dogs had picked up the waft of cannabis coming from the Vincents’ flower bed in the Warwickshire village of Bidford-on-Avon.

Nonplussed, the couple allowed the drug squad into their detached, four-bedroom home – and the mystery was solved.

The source of the smell was not marijuana plants but a common evergreen creeper,  moss phlox.

Mrs Vincent, 57, a cashier with the  Nationwide, had been cultivating the flowering plant for years.

Her 58-year-old husband, a shopkeeper, said: ‘My wife’s a keen gardener. When we bought the house, the plant was already there – but then it grew and grew.

‘We didn’t know what it was – we just thought it was quite pretty. But teenagers kept coming to the door saying, “Sorry, mate, we can smell ganja … you got any?”

‘I’d say, “No, I haven’t got anything”.  They were real hoodies but also strangely polite, obviously thinking that I was some mean drug dealer.