An estimated €2 million worth - 129 kilograms - of amphetamines was found during a random search of a Spanish truck in western Germany on the border with Luxembourg.
The unnamed 55-year-old driver was arrested. The illegal substance had been packed into six sport bags, officials said.
The find is the biggest synthetic drug haul German authorities have made in the past five years, said the investigating state prosecutor in the nearby city of Trier in Rhineland Palatinate on Wednesday.
Initial information suggests the amphetamines had been destined for southern Europe, investigators said.
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