A top Berlin hospital plans to investigate the conduct of drug trials in the former East Germany amid allegations that some patients were used as human guinea pigs.
Communist officials allowed Western firms to test new drugs on about 50,000 people, often without their knowledge, the news magazine Der Spiegel says.
Now the Charite hospital says it will stop shredding old patient records and investigate what happened.
The tests took place in the 1980s.
Der Spiegel says it got the information from former East German health ministry records, the old Stasi secret police files, the former state's pharmaceutical authority and private collections.
Drug companies from West Germany, Switzerland and the US allegedly offered up to 800,000 Deutschmarks (about 400,000 euros; $520,000) per clinical study - foreign exchange that was much needed in the underfunded East German health service.
In a statement, the Charite hospital said that "as a first step, Charite has stopped the usual shredding of decades-old files after expiry of the storage period. This is in order to reconstruct the course of action in particular cases as fully as possible."
Prof Volker Hess of Charite's medical history institute said the conduct of the East German clinical trials should be re-examined, to find out the degree of patient consent and how undesirable side-effects were handled. The study should also compare East Germany's medical procedures with those that were standard in the West at the time, he said.
Germany's Union of Research-based Pharmaceutical Companies (VFA) welcomed the idea of researching the old East German clinical trials. The VFA's members account for about two-thirds of the German pharmaceutical market.
"According to our knowledge, the standards for clinical trials in the GDR corresponded to the prevailing standards at the time," said the VFA's chief executive Birgit Fischer. "GDR law provided guidelines for clinical tests which were comparable with those of Western states and the US."
More than 50 East German hospitals were involved in the clinical trials, Der Spiegel reports. It says the Western drug companies that took part included Bayer, Schering, Hoechst and Sandoz, which is now part of Novartis.
In statements to the Associated Press news agency, spokesmen for Novartis and Bayer said their clinical trials, to their knowledge, conformed with ethical and legal standards.