Divided into 1.3 million doses, the heroin is estimated to have a street value of €50 million.
According to the Criminal Investigation Division (BKA), the shipment was discovered on September 22 in a truck that had travelled to Germany from Iran.
Two Syrian brothers, aged 30 and 35, were arrested in Essen and Cologne in September and are believed to have leading roles in the drug ring.
Both were suspected of owning businesses that were fronts for the import of heroin into Germany.
Their information led to the arrest of a Dutch man in Belgium and the eventual seizure of the truck.
The BKA believe that a Syrian-Iraqi drug ring has been smuggling large volumes of heroin into Western Europe, hidden in vegetable shipments, for years.
In all of 2013, the BKA confiscated 270 kilogrammes of heroin nationwide.