Boxing Olympic champion Manfred Wolke has died at the age of 81, former boxer Henry Maske told dpa on Monday with reference to the family. Wolke died last Wednesday after a long and serious illness, Maske said. Wolke is survived by his wife and three children. Representing East Germany, he was the welterweight Olympic gold medallist at the 1968 Mexico City Olympic Games. After his boxing career ended, Wolke became a coach, most notably working with 1990s heavyweight contenders Axel Schulz and Maske. Wolke helped Maske to become a middleweight Olympic champion in Seoul in 1988. He also led Rudi…