He grew up in the ruins of post-War Dresden. He became a painter and was thrown out of the Dresden art school. In Berlin he formed a punk rock band, and became friends with a poet who betrayed him to the Stasi. It was all part of the swirling underground art scene in East Berlin in the early 1980s. Many of the leading writers, painters and political activists of the day were informed on by Sascha Anderson.Now, Ralf Kerbach is a professor of painting back at the Dresden College of Fine Arts -- the same institution, he tells Tom Morton, that expelled him. Also speaking to Tom Morton is Alison Lewis, the author of a book about the poet Sascha Anderson and his collaboration with the Stasi.