Someone who refused to be charmed was the historian-commentator Götz Aly. In 1989 Aly reacted to the appearance of Gerstner's autobiography with a powerfully critical piece in Gerstner's old newspaper, the Berliner Zeitung. Researches in the Stasi records showed that Gerstner had been registered with the ministry as an informer since 1975. He had been identified in Stasi files under the code name "IM Ritter", a characteristically ironic choice of name, since apart from "Ritter" being the German word for "knight", Gerstner's biological father had been the Nazi diplomat Karl Ritter. The Stasi had paid Gerstner a supplementary salary amounting to 2,000 marks per month for his information. Aly adduced the example of the remarkable East German actor-singer Manfred Krug. The relevant information was already in the public domain, since it had been disclosed in Krug's own memoires. In 1976 Krug was banned from performing in public because he participated in protests against the expulsion from the country and deprivation of citizenship suffered by his friend, the popular singer Wolf Biermann. In 1976, unable to work as a stage-performer in East Germany, Krug had applied for permission to emigrate. He had received a visit from Gerstner in April 1977. During the visit, Krug said Gerstner had suggested that he (Krug) might consider working for the Ministry for State Security (Stasi). The report of Gerstner's visit to Krug is also documented in the Stasi records. The report from "IM Ritter" included the information that Krug had kept a diary. It stated that Krug had taken him to be a Stasi informer, but after a while had nevertheless relaxed enough for an open discussion to take place between the two men. In his 1999 autobiography Gerstner had indeed written of how he had reported on conversations with foreign diplomats to the HVA (which was the foreign intelligence branch of the Ministry for State Security). In March 2000 he took the opportunity to publish in the Berliner Zeitung a ferocious rejection of Aly's piece, which appeared under the headline "Weder ein Held, noch ein Feigling" ("loosely "Not a hero, nor a coward"") and was described as "Ein besonderer Leserbrief" (""A special [kind of] reader's letter""). Gerstner wrote: "Ali asserts that I concealed my activity for the Stasi in the book.