The cocaine was found in more than 1,700 tin cans that had been filled with putty, Hamburg's customs office said.
ADVERTISEMENTCustoms officers in Germany say they have made Europe's largest-ever seizure of cocaine.
They found more than 16 metric tonnes in containers that had arrived from Paraguay, authorities in Hamburg announced on Wednesday.
The drugs were discovered on February 12 during a search of five shipments that had been flagged as suspicious.
The cocaine was found in more than 1,700 tin cans that had been filled with putty, Hamburg's customs office said.
Over the following days, German and Dutch authorities investigated further and another 7.2 metric tonnes of cocaine were seized on Sunday in the Belgian port of Antwerp.
The total haul of more than 23 tonnes would have had a street value of "several billion euros", officials said.
On Wednesday, Dutch authorities arrested a 28-year-old man from the town of Vlaardingen, near Rotterdam, who is suspected of being responsible for the shipments.
"With this blow against organised narcotics crime ... the German customs have once again impressively demonstrated their clout," said Rolf Bösinger, Germany's State Secretary for Customs at the Federal Ministry of Finance.
Berlin has also thanked the "exemplary cooperation" of European partners in the operation.