Four people were arrested on Tuesday following police raids on homes and business premises used by a company suspected of being a wholesale supplier of equipment to the illegal marijuana cultivation industry.

Several properties, boats and cars were sequestered following the raids, which involved sealing off part of the Ravenswade industrial estate in Nieuwegein. Some five lorries and cars were also stopped while driving orders to customers and their contents seized, the police said in a statement.

The raids follow an investigation of over a year. Legislation making it a criminal offence to help people grow marijuana came into effect on March 1 2015. If found guilty, so-called facilitators can be jailed for up to three years and fined €81,000.

Police suspect the wholesale operation closed down on Tuesday to be the biggest supplier in the Netherlands and possibly the rest of Europe.

The company’s records show that its client base is almost entirely made up of companies which are active in marijuana cultivation and this indicates it is an ‘essential link’ in large scale growing, the police said.

Fertiliser

Among the goods found in the warehouses were huge amounts of fertiliser, filters, insulated ventilators and other equipment needed to set up an illegal plantation.

The company, listed in Chamber of Commerce documents as Het Groeipaleis, had annual turnover of between €25m and €30m, the NRC said. The company advertises itself as a traditional supplier of garden supplies and its product line includes hydroponic indoor systems.

The paper’s investigation shows that two local men own the wholesale company, which is at the middle of a web of other companies. One of them also runs an employment agency with lots of contracts for people to transport flowers and plants, the paper said.