Belgian customs recently found about 1 tonne of cocaine while checking a container in Antwerp Port, the Finance Department announced on Wednesday.
The seizure dates back to 25 September.
The drugs were hidden in a container that had arrived in Antwerp from Panama and was to travel on to the Netherlands. Investigators are still trying to determine who is responsible for the shipment.
On Monday, the Finance Department had also announced the discovery of more than six tonnes of cocaine earlier that day at a quay in Antwerp. Those drugs had been hidden in two containers from Suriname.