Former Stasi chief dies

Markus Wolf, said to be the model for Karla in the John LeCarre thriller Tinker, Tailor, Soldier, Spy, was 83.

Wolf took a long-term approach to his job, introducing spies into West Germany among the stream of East Germans who fled before the Iron Curtain was imposed.

Sometimes he waited years for his sleeper agents to work their way into high office so that they could begin supplying him with secrets.

One such agent was Gunter Guillaume, who moved to West Germany in 1956. He worked his way up the hierarchy of the Social Democratic Party (SPD), eventually becoming a close aide of the Chancellor, Willy Brandt, and getting his hands on important Nato secrets.

In 1974, he was unmasked by West German intelligence officials and the resulting scandal led to Brandt resigning.

Later Wolf said he had not sought Brandt's downfall - and that the affair had been one of the biggest mistakes of the Stasi.