A Dutch scheme to give people “scratch and sniff” cards that smell like marijuana is set to be rolled out across the country after a pilot was hailed as a great success.

People across the Netherlands are now being encouraged to familiarise themselves with the aroma so that they can detect if their neighbours are operating illegal plantations.

The cards read: “Scratch, sniff and help. With this cannabis-scented card you will recognise the smell of marijuana cultivation.”

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The initiative is being backed by police, city councils and energy service providers, who lose out to the tune of hundreds of millions of pounds every year because of growers illicitly tapping into the energy network.

Martijn Boelhouwer, a spokesman for the scheme, told the AFP news agency: “The cards are being made available across the country, starting with four cities this week. We hope other cities will follow.”

Those four cities include Amstelveen near Amsterdam, Mr Boelhouwer said, after the number of reported plantations surged in the wake of the cards being introduced to The Hague and Rotterdam.

The Dutch daily newspaper Trouw reported that the proportion of people able to detect the signs and smells of cultivation went up from 40 per cent to 60 per cent during the trial.

Mr Boelhouwer said that they are cracking down on illegal cannabis cultivation – which is nonetheless tolerated by police when no more than five plants are being grown for personal use – because faulty wiring and electricity connections create serious fire risks.

“At least 20 per cent of all industrial fires are caused by illegal marijuana cultivation,” Danielle Nicolaas, a spokeswoman for energy company Stedin which forms part of the project, told AFP.

There are around 30,000 illegal cannabis plantations across the Netherlands, and police estimate that cannabis was a €2.2 billion industry in 2012 – mostly controlled by criminal gangs.