A statement from the Federal Prosecutor, Alexander von Stahl, said Klaus Croissant, 61, was charged with spying on the Greens party and other left-wingers in West Germany and the European Parliament from 1981 to 1989.
Mr Croissant is said to have enlisted his girlfriend as an informer for East Germany's Ministry of State Security, the Stasi, which acted as an espionage agency abroad and security police at home. In the 1970s, Mr Croissant defended Ulrike Meinhof and other leaders of the Baader- Meinhof guerrilla gang, which later became known as the Red Army Faction (RAF).
After fleeing to Paris in 1977 to escape investigation, he was extradited to West Germany and sentenced to more than two years in prison for supporting terrorism. Mr Croissant has remained in jail since being arrested in September, Mr Stahl said. Charges were brought in court last month but only announced now.
The Stasi is alleged to have led Mr Croissant under the codename 'Thaler' and his partner, Brigitte Heinrich, a Greens MEP as 'Beate Schaefer'.
After Heinrich's death, Mr Croissant is said to have remained at the parliament as a Greens assistant. He is alleged to have been paid DM71,000 ( pounds 29,500) by the Stasi for his spying. Links between the Stasi and RAF guerrillas came to light after the collapse of East Germany in 1989.
As Germany prepared to unite, police found 10 former RAF guerrillas who had retired to East Germany under Stasi protection to lead ordinary lives under new identities.Reuse content