The Sicherheitspolizei (SiPo) was the state political and criminal investigation security agency of Nazi Germany from 26 June 1936 to 22 September 1939, serving as a merger of the Gestapo and the criminal police. The SiPo was led by Interior Minister Wilhelm Frick and police chief Heinrich Himmler, while its executive was Reinhard Heydrich. In 1939, the SiPo was merged into the Reich Main Security Office.