Police officer Vincent Loyens of Lanaken and Maasmechelen police: "Cannabis farms are often discovered by accident, when there is a fire or a water leak or if the police are tipped off."
Mr Loyens suspects many Belgian cannabis farms are being left untouched. He points to the situation in the Netherlands where there is practically a cannabis farm in each and every street along the border.
"What the police discover is the tip of the iceberg. We don't have the resources to launch targeted searches. If we uncover one in ten, we're doing a great job."
More and more cannabis farms are appearing in other parts of Belgium. Commissioner Benny Van Camp of the Federal Police Drugs Unit: "The problem really isn't limited to the Kempen District or Limburg."
Cannabis farmers have been setting up store in central parts and are today surfacing in Wallonia.