In 1909 he fell ill. Neighbours summoned a doctor, but he met with such resistance when he attempted an examination that he had to leave without making a diagnosis. Michael poisoned himself overnight. Examination of the body disclosed that he was female-bodied.
- Arthur Koestler & Norman Haire based on the work of Magnus Hirschfeld. Sexual Anomalies and Perversions Physical and Psychological Development, Diagnosis and Treatment : a Summary of the Works of the Late Professor Dr. Magnus Hirschfeld. London: Encyclopaedic Press, 1952: 223.