Thanks to Lehmann's information, the Soviets were able to free their agent Arnold Deutsch, who later recruited Kim Philby.

Toward the end of June, Hermann Göring asked Lehmann to help organize the Röhm Putsch to liquidate opponents of the regime.

Lehmann later told the NKVD that the murders he helped organize during the Night of the Long Knives sickened him, albeit they also solidified his position with his Gestapo superiors.

On 19 June 1941, Lehmann reported to the NKVD the exact date and time when the Germans planned to invade the Soviet Union.

In 1942, with the Germans' discovery of the Red Orchestra, Lehmann was arrested and shot without trial on orders of Heinrich Himmler, who at the same time had the entire matter hushed up.