Electricity network company Stedin identified almost 1,600 marijuana plantations in the central urban belt of the Netherlands last year.

This is a rise of 3% on 2013, Stedin said.

The increase is due to a more pro-active approach to potential electricity theft. ‘At the same time, the dangers of growing marijuana and the importance of reporting it have not yet got through to the general public,’ anti-fraud chief Peter van ‘t End told news agency ANP.

One in five of the plantations involved illegally tapped electricity, which boosts the risk of short-circuits and fire. ‘This is extremely dangerous, not only for the tenant but for their neighbours,’ Van ‘t End said.

Experts estimate there are around 30,000 marijuana plantations in the Netherlands.