Markus Wolf, the former head of the ex-East German foreign intelligence division of the Ministry for State Security (Stasi) died Thursday at the age of 83, his family reported.
His family said he died in his sleep overnight at his home.
He was number two in Stasi during most of the existence of the GDR.
Wolf was known as the "man without a face" because he kept such a low profile that Western intelligence services did not have his picture.
After German reunification in 1990, Markus Wolf faced two trials for his espionage activities during the Cold War.
In the second of these, in May 1997, he was given a two-year suspended jail sentence on kidnapping charges.
In the past Wolf managed to steal NATO secrets for the Soviet bloc that could have been decisive if war had broken out in Europe. He is believed to have infiltrated some 4,000 in the West.