German Federal Police discovered drugs worth 904,000 dollars hidden in 52 Lego boxes in a car they checked on the A3 motorway near the Dutch border.
According to the police, the drugs weighed 83 kilogrammes.
The two people in the car were arrested, investigators said on Tuesday.
The women, aged 22 and 24, were caught on April 10.
They had 51 kilos of ecstasy and about 32 kilos of amphetamines stashed between the 52 identical Lego boxes.
The two Dutch women are being investigated for violations of the narcotics act.