Cannabis "scratch and sniff cards" issued to Dutch citizens

In a novel bid to combat illegal cannabis cultivation, Dutch authorities started handing out 30,000 cards with a marijuana odour Monday to alert citizens to what their neighbours may be up to.

"Citizens must be alerted to the dangers they face as a result of these plantations, and if they become aware of any suspect situations they must report them," Arnie Loos, spokesman for a government-appointed working group on cannabis cultivation, told journalists in Rotterdam.

Though it remains technically illegal, the Netherlands decriminalised the consumption and possession of under five grammes (0.18 ounces) of cannabis in 1976 under a "tolerance" policy.

Citizens may grow no more than five plants for personal use. Bulk cannabis cultivation and retail remain illegal and are in the hands of criminal organisations in a black-market business worth some two billion euros (2.8 billion dollars) per year.

"Assist in combatting cannabis plantations!" reads the green scratch-card of about 20 centimetres by 10 (eight inches by four) being distributed to residents of the western cities of The Hague and Rotterdam.

With two boxes that release a cannabis odour when scratched, the card also lists a police telephone number.

Organisers said this was a first for the Netherlands, and a pilot project for possible expansion.

"If people do in fact call the number listed on the card, we could make this a national operation," Loos said.

Authorities believe there are some 40,000 illegal cannabis plantations in the Netherlands - hidden away in attics, apartments or warehouses.

About 6,000 plantations are busted every year.

Of these, about 300, each with between 600 and 1,000 plants, are uncovered in Rotterdam alone, said Richard Anderiesse, a spokesman for the port city's cannabis task force.

Renee de Bruin, spokeswoman for gas and electricity distribution company Stedin, said illegal plantations posed a high risk of fire as the illegal tapping of water and power often led to short circuits.