In a recent newspaper article about a Jewish man concealing his identity in Norway during the five years of Nazi German occupation, a reference is made to a "secret Communist group" among German troops stationed outside Oslo. The article in Norwegian is here, the relevant passage is
Av landhandlerkona Johansens erindringer fremgår det også at flyktningene faktisk fikk hjelp fra to av okkupasjonsmaktens soldater. Østerrikeren Joseph Kraval, leder av en hemmelig kommunistisk gruppe blant troppene i Maridalen, klarte sammen med en kamerat å smugle koks ut av leiren om natten og bære den gjennom skogen til hytta.
In the recollections of the shopkeeper's wife, Johansen, it emerges that the refugees actually obtained help from two of the soldiers of the occupying power. The Austrian Joseph Kraval, leader of a secret communist group among the troops in Maridalen, managed, together with a friend, to smuggle coke (fuel) out of the camp at night and carry it through the woods to the cabin.
The shopkeeper, Johansen, is earlier in the article said to have been a member of the Communist resistance, so his wife might have been prone to exaggerating the Communist-ness of the German soldiers. Perhaps unsurprisingly, I found no relevant Google results for the name of the soldier. Wikipedia's article on German resistance to Nazism focuses on resistance among the elite and among those staying in Germany.
Does any documentation exist of Communist resistance groups in occupying German armies (in any country) during the Second World war? I would be interested both in information about successful ventures (also small-scale like in the example above) and in groups that were outed during the war.
I am primarily interested Communist resistance not driven by Soviet interference, though I realize the difference may be hard to tell. I do expect the influence of Soviet agents in Norway 1940-45 to have been very limited, though.