The Dutch authority on consumer and markets ACM launched an investigation into whether companies operating in Dutch ports made illegal price agreements, or are guilty of so-called cartel formation. The companies investigated all work in the bunker sector, which supplies ships with fuel, NOS reports.

The ACM suspects that the companies made agreements to keep the price for ship fuel artificially high. Several companies working in the triangle between the ports of Rotterdam, Amsterdam and Antwerp, Belgium are under investigation. Dozens of bunker sector companies are active in that region.

The investigation was launched based on a tip from the Public Prosecutor. The ACM already visited several companies, and will continue the investigation in the coming months. Companies found guilty of forming a cartel can be fined up to 40 percent of global sales, according to ANP. The persons who lead a cartel can be fined up to 900 thousand euros.

The bunker sector is responsible for producing, trading, storing and transporting gas oil and fuel oil.