In 1972 he founded the Friedrichshof Commune, which has been viewed by some as an authoritarian sect, and that existed for several years before falling apart in the 1990s. In 1991, Muehl was convicted of sexual offences with minors and drugs offences and sentenced to 7 years imprisonment. He was released in 1997, after serving six and a half years, and set up a smaller commune in Portugal. After his release, he also published his memoirs from the prison ("Aus dem Gefängnis").