German right-wing activist who arose in the wake of Ernst Röhm, the long-time leader of the Sturmabteilung (SA), the Nazi Party’s original paramilitary wing.
In the mid-1920s, Röhrbein took on leadership roles in the radical right-wing combat organization Frontbann founded by Röhm. In particular, Röhm – with whom he is said to have had a homosexual relationship – entrusted him with the management of the so-called “Frontbann-Nord”, the Berlin section of the organization. He chose the young Karl Ernst as his adjutant; Ernst later became head of the SA in Berlin-Brandenburg. Ernst, with whom he also was rumoured to have had a homosexual relationship, was nicknamed “Frau von Röhrbein”. Walther Stennes’ followers referred to the alleged gay trio as “Röhm-Röhrbein-Ernst”.
In the summer of 1933 Röhrbein was taken into “protective custody” for unknown reasons, perhaps due to the unsubstantiated claim that he had had something to do with the Reichstag fire of February 1933.
After his arrest, Röhrbein was initially housed as a “protected prisoner” in the Berlin Moabit prison and then transferred to the arrest area of ??the Munich police department. From there he was taken to the Dachau concentration camp for a while, after trying to smuggle letters out of custody to inform Hitler and Karl Ernst of his fate. These letters are said to have been intercepted and sent to Röhm, who immediately ordered Röhrbein’s transfer to Dachau on 10 August 1933.
On 13 September 1933, Röhrbein was finally – supposedly at the instigation of Karl Ernst and other Berlin friends – taken from Dachau to the Löwengrube prison and from there to the Stadelheim prison at the end of the year. On 27 February 1934 Röhrbein was taken back to Dachau.
On the night of 30 June to 1 July 1934, Röhrbein was shot and killed by members of the Dachau SS camp guard during the Röhm affair. The official death certificate of the registry office in Prittlbach stated that the time of death was 3:00 a.m. It remains unclear whether his execution was due to an order coming from Berlin or whether it was an arbitrary act by the camp manager Theodor Eicke.

Link to Wikipedia biography (German)