At least a couple of minor early Nazis were. After the war ended, but before Hitler was demobilized, he was tasked by his commanding officers, one Captain Mayr, acting under General Ludendorff, with infiltrating and keeping tabs on the then German Worker's Party.

After a few months of this, he'd not only convinced both Mayr and Ludendorff that the party wasn't a threat to Germany, but had recruited them both to the party, as well as taking control of the party and renaming it.

Mayr quickly became disillusioned, became a critic of the Nazis, and eventually died in a concentration camp during the war. Ludendorff stayed to take part in the Munich putsch, and was involved in right wing politics for a whlie thereafter.