Lutz Riemann (acting here as First Police Lieutenant Zimmermann) was from 1966 onward employed as undercover informant of the East German Security Police (IM des Ministeriums für Staatssicherheit aka 'MfS'), his operational cover name was 'Richard König'. He covertly provided information and spied on his peers and colleagues from 1966 until 1989. Confronted in 2013 with evidence from the Rosenholz files exposing his clear-name, Riemann stated that he had committed himself to this undercover work out of "ideological reasons" and that he "was a communist and always will be".