BERLIN -- A married couple went on trial in Germany on Tuesday accused of handing hundreds of sensitive NATO and European Union documents to Russia during a two-decade spying career that continued well beyond the end of the Cold War.
Federal prosecutors accuse Andreas Anschlag and his wife Heidrun -- suspected Russian citizens whose names are aliases -- of entering West Germany in 1988 with forged Austrian passports and fabricating a suburban middle-class existence to cover their espionage.
So perfect was the subterfuge that even their own daughter did not know of their spying, German media reported.
Russian President Vladimir Putin worked for the Soviet intelligence agency the KGB in East Germany in the 1980s when the couple are accused of having started their career.
"This is a case of treason that has been going on for more than 20 years, involving the entire range of intelligence activity, from trying to recruit new sources to instructing others, all the way to writing their own reports on political and military matters," federal prosecutor Rolf Hannich said.
"These are documents and evaluations on NATO's policies which are of course of high interest to the other side because they can then adapt their own behavior."
The couple said nothing at Tuesday's court hearing. In Germany, the accused are not required to submit a plea.
The indictment said one of the sources for the secret documents procured by the Anschlags was a person working for the Dutch foreign ministry.
German special forces arrested them in separate raids on their family home in Marburg, central Germany, and on an apartment near the southwestern city of Stuttgart in the early hours of October 18, 2011.
According to reports, Heidrun Anschlag was at home in the process of receiving radio messages from Moscow when the Marburg raid took place at what they described as a typical, middle-class suburban family house.
Hannich said the prosecution's task had been rendered more difficult because the couple had already been preparing their return to Russia and had destroyed many documents from before 2008.
Documents obtained by the couple related to such matters as NATO's political and military affairs, the EU's military, police and civil missions, political negotiations on EU bodies and the situation in eastern European and Central Asian countries.
Economic ties between Russia and Germany are booming but Chancellor Angela Merkel, who grew up in former communist East Germany, has also criticized Moscow's human rights record and clampdown on political dissent.
In Germany, spying can be punished by up to 10 years in jail.