Dutch sniff cards to help find cannabis plantations Published duration 8 November 2010

image caption Authorities say the scheme could be extended across the Netherlands

About 30,000 Dutch households are to receive marijuana-scented scratch cards in an effort to uncover illegal urban cannabis plantations.

Authorities in Rotterdam and The Hague say they are distributing the cards to help people recognise what cannabis smells like.

The cards also include a number to call to report suspected marijuana-growing.

Dutch authorities turn a blind eye to citizens growing up to five marijuana plants for personal use.

"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," said the spokesman for government-appointed working group to combat cannabis cultivation in the Netherlands, Arnie Loos.

The green scratch card, measuring 20cm by 10cm (8in by 4in) reads "Assist in combatting cannabis plantations".

When scratched, the card reveals its scent as well as a police number people can call if they suspect that a neighbour grows marijuana on a large scale.

The card also lists other indicators of urban cannabis cultivation, such as the buzzing sound of ventilators, suspicious connections to electricity supply points and curtains that are kept closed.

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

Dutch authorities say the plantations are a hazard which can cause fires or accidents because of the cables and lamps needed to maintain a cultivation temperature of 27C.

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

Each year, about 200 plantations are discovered in Rotterdam alone.

In 1976, the country decriminalised the consumption and possession of up to five grams of cannabis.