Investigators raided numerous houses and carried out multiple arrests in drug raids in Germany, Spain and the Netherlands on Monday.
According to German police, 14 properties were searched in the states of North Rhine-Westphalia and Lower Saxony, during which three people were arrested and 100,000 euros (116,000 dollars) in cash was seized.
Spanish police simultaneously raided six properties and made three arrests, seizing 1,200 marijuana plants; while in the Netherlands, the police confirmed they had searched one property, but declined to give further details due to the ongoing nature of the case.
"In the fight against organized crime, we not only have staying power, but also a long arm.
This is shown not only by the arrests in Gelsenkirchen and Bochum but also by those in Spain and the Netherlands," North Rhine-Westphalia's Interior Minister Herbert Reul said.
He added that it was the international coordination between national police forces that allowed the police to arrest so many on Monday.
"I am glad that as of today they can no longer enrich themselves with their drug deals on the suffering of addicted and sick people," he said.