After the invasion of the Wehrmacht early in 1941, the Cultural Association was disbanded and VoMi organised the Deutsche Volksgruppe in Serbien und Banat (DVSB) under Janko's leadership.

Janko and the DVSB cooperated fully with VoMi, and as a step in the minority's total Nazification, it even introduced a system of classifying the local Volksdeutsche similar to that used by the DVL in Poland.

Heinrich Himmler responded with dismay: “Es ist unmöglich, dass Deutsche in Europa irgendwo als Pazifisten herumhocken und sich von unseren Bataillonen beschützen lassen …“ ("It is impossible that Germans can be sitting around somewhere in Europe as pacifists and be protected by our battalions ...")[4] Janko responded by offering to set up a regiment of about 3,000 local ethnic Germans, with limited service interaction with the Wehrmacht and Waffen-SS.

[citation needed] In his book (referenced below) Sepp Janko bragged about his ability to recruit sons of ethnic Germans from Banat region.

This excerpt was used in Nuremberg war crimes trial in May 1946: “ … I put at the disposal of the Fuehrer almost the entire German national group in the former State of Yugoslavia and gave him so many volunteers as soldiers, is to me a subject of great pride.

"[2]Janko was able to escape the National Liberation Army (Yugoslavia) in late 1944 to Austria, where he was arrested by United States forces and taken to the Wolfsberg camp in Carinthia.