Iran expelled a German diplomat for "undiplomatic" behavior, the Foreign Ministry confirmed on Sunday. "Responsible authorities recognized that this person was engaging in undiplomatic behavior and has to leave Iran," Mohammad Ali Hosseini told reporters during his weekly briefing, without revealing the diplomat's name or giving any additional information. A German Foreign Ministry spokeswoman said late Saturday that she could only "confirm that a German diplomat has left Iran," but declined to elaborate. The expulsion of the German diplomat comes in the wake of Germany's reported expulsion last July of an Iranian consular attache from Germany. German weekly Der Spiegel reported last month that the Iranian diplomat identified only as Mohraramali D., had contacted a specialist firm in Bavaria, apparently in hopes of buying a component that could be used in the uranium enrichment process. The Foreign Ministry in Berlin refused to confirm the report at the time and declined to do so again Saturday. Germany is one of three European powers negotiating with Iran over Tehran's nuclear program. Germany has strongly opposed any alleged Iranian efforts to develop nuclear weapons but has adopted a softer tone in dealing with Iran's nuclear program than Britain and France. German Chancellor Angela Merkel, however, has shown a tougher stance towards Iran when she said in February 2006 that the world must act to stop Iran from developing a nuclear bomb. Relations between Germany and Iran have traditionally been one of the closest between any western nation and Iran since its 1979 revolution. Germany and Iran were once major trading partners but relations were frozen after a German court ruled in 1997 that the 1992 shooting deaths of four Iranian Kurdish dissidents in Berlin had been ordered at the highest levels in Tehran. Two men convicted of the 1992 assassination were released from prison last month. The case of Helmut Hofer, a German businessman twice sentenced to death in Iran for a relationship with a 26-year-old Iranian medical student, further strained ties. Hofer was eventually acquitted and released from prison in 2000. Relations significantly improved after the visit to Germany of former reformist president Mohammad Khatami in 2000 but ties were strained once again in 2004 with the unveiling of a plaque in Berlin 1992 killing of the four dissidents and holding Iran to blame. In response, Iranian war veterans unveiled a plaque outside the German Embassy in Tehran accusing Germany of supplying chemical weapons to Iraq during the Iran-Iraq war of 1980-88. Cultural officials, however, have been at work to improve ties. A German symphony orchestra played Beethoven and Brahms in Teheran in a rare visit by a European ensemble last August.