The man and the woman, who were arrested in October 2011, are alleged to have been operating in Germany for over 20 years. They have been charged with espionage in the first such case since German unification.

"The accused had the task of gathering information about the political and military strategy of the EU and NATO," the prosecutor's office said, as well as "security-relevant political aspects of relations between Germany, the EU and NATO to Russia."

Watch video 00:33 Espionage

An alleged spy in the Dutch Foreign Ministry supplied them with secret European Union and NATO documents from 2008 to 2011.

The couple was arrested last October when police raided their home, reportedly catching the woman listening to coded messages.

Germany's domestic intelligence services discovered the couple after they got a tip from the United States, where the FBI had received information from a Russian defector.

The accused were reportedly born in South America and entered West Germany in 1988 using fake Austrian passports. This was one year before the Berlin Wall fell when the Russian foreign intelligence service SVR was still the Soviet Union's secret service KGB.

The pair married and reportedly had one daughter. They led an inconspicuous middle class life first in a small town near Bonn, then in Hesse, where they were arrested in October 2011.

According to German media reports, they received a joint annual salary of nearly 100,000 euros ($130,000) for regular reports.

According to the defense lawyer the accused refuse to testify in court.

If found guilty they could face prison sentences of up to 10 years.

rg/sej (dpa, AP, AFP)

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