MADRID (AP) — Spanish police have confiscated a huge hemp plantation in the northern province of Navarra and arrested three suspected growers, Spain’s Civil Guard said Wednesday.

The Civil Guard said the 1,025-acre ((415-hectare) plantation was the largest of its kind in Europe.

Police said the owner reported that his crop was for industrial use. But investigators suspected the hemp plants were being sent to Switzerland and Italy to be turned into cannabidiol, or CBD, the production of which is illegal in Spain.

Police destroyed 415,00 plants that they think were intended to be sold for some 30 million euros ($32.5 million). Third parties in foreign countries would then process the plants into cannabidiol, or CBD, worth around 100 million euros ($108 million), Spanish police said.

Three individuals were arrested in Navarra. Two others are under investigation in the neighboring Basque Country region.