Funny, Lanfranc, but no, Horst Wessel was a member of Hitler's Sturm-Abteilung (SA, tormmtroops, the military wing of the Nazi party, sometimes better street gangs) who wrote the official SA song. This song was considered as an anthem then and always was played after the official National Anthem.
He was allegedly killed by communists; some said, since he was a pimp in Berlin that he was not KIA for political reasons but for some other related to this profession. But may it be as it was : only dead nazis are good nazis.

Wilfried