A former government minister, Wolfgang Clement, told news agency dpa on behalf of Ehmke's family that he died at a Bonn hospital yesterday.
Ehmke, a member of Brandt's centre-left Social Democratic Party, joined the Cabinet as justice minister in 1969 and a few months later became Brandt's chief of staff. He helped implement Brandt's drive for reconciliation with the communist bloc, the so-called "Ostpolitik".
The Social Democrats' general secretary, Katarina Barley, tweeted today that "without him, Willy Brandt would not have become THE chancellor".