Eleven people between the ages of 24 and 44 were arrested in Germany, France, the Netherlands, Poland and Spain during the investigation into the Chemical Revolution marketplace.
German authorities announced on Friday that they had shut down the country's largest online drugs store, Chemical Revolution, and arrested 11 people.
The website sold amphetamines, MDMA, cocaine, heroin, ecstasy, LSD and cannabis to clients all over the world who paid with the Bitcoin crypto-currency, the German Federal Criminal Police said in a statement.
The operation started in the spring of 2018 with the arrest of a 26-year-old man in Brandenburg, eastern Germany.
"Considerable amounts of narcotics were seized" at the time, including nearly 50kgs of amphetamine and 2kg of MDMA.
A further 10 people between the ages of 24 and 44 were arrested between February and May 2019 by authorities in Germany, France, the Netherlands, Poland, and Spain.
In addition to selling on their own platform, the group also sold the illicit substances on the "Wall Street Market", the world's second-largest Darknet platform, which sold drugs, counterfeiting and malware before it was shut down by German authorities in May.