Siggi Grünewald was born in 1945 in Thuringia. She grew up in a social democratic family in West Berlin. During a trip to the GDR she met her future fiancé. She organized his escape from the GDR, not knowing that the people who were helping her worked for the Ministry of State Security.
In 1981, she was arrested and sentenced to five years and six months in prison on the grounds of "subversive man trade." The following year, the Federal Republic of Germany paid for her release, so she could return to West Germany. Since 2012, she has worked as a tour guide at the Berlin-Hohenschönhausen Memorial.