Gunter Guillaume

KGB-trained East German spy who entered West Germany under the cover of a "refugee," then infiltrated the Social Democratic Party along with his wife and fellow double-agent, Christl. Christl became a secretary in the office of the Chancellor, Willy Brandt, and Gunter soon joined the administration as one of Brandt's three personal assistants. All the while, he passed top-level intelligence to the KGB and Markus Wolfe's East German Ministry for State Security.

A Soviet defector eventually betrayed him, and Guillaume was arrested in 1974 -- to the overwhelming embarassment of Willy Brandt and his government. Brandt was forced to resign. Guillaume, meanwhile, received a 13-year prison sentence while his wife was sentenced to nine years. Both were released early, in spy swaps with East Germany .