Container company ECT, the biggest at Rotterdam port, is suspected of market manipulation, the Financieele Dagblad reports on Thursday.

According to anonymous sources, the Dutch consumers’authority ACM raided ECT last summer and found it was giving priority to inland shippers it hired itself to take goods to and from the port in its European Gateway Services. Several inland shippers working independently of ECT told the FD they lost out on work. This is against competition law.

The FD says its sources want to remain anonymous because of the powerful position ECT holds within the port.

According to these sources the ACM raid took place in August 2014 when several managers were questioned and computers were seized.

An ACM spokesman would neither confirm nor deny the raid to NRC on Thursday. ECT would not comment, the paper says.