A report by German newspaper Der Spiegel claims more than 50,000 people in East Germany were used as medical guinea pigs between 1983 and 1989 without their knowledge or consent.
The scandal was first uncovered last December, but the victims were originally thought to be far fewer.
The deal with East Germany’s Health Ministry allowed pharmaceutical trials to be carried out in exchange for foreign currency.
“It shows that the German Democratic Republic, wanting to get foreign currency, was not considerate of the patients. And that the Ministry of State Security, that is the Stasi, monitored this trade that brought in foreign currency, and made sure that no disturbing influences prevented that business,” said Federal Commissioner for the Stasi archives Roland Jahn.
East German authorities received around 430,000 euros when they let 50 Western pharmaceutical companies carry out 165 medical tests.
Christoph Bergner, the member of government responsible for matters relating to East Germany, has called for an inquiry.