The family of the Austrian artist have taken the tentative first step in opening up his archive of works, which range from the depiction of ordinary German soldiers to the destruction and despair of Berlin in the closing days of the Second World War.
Germany had up to 80 official war artists and Zenzinger, a fellow Austrian, was retained by the German military's Division of Visual Arts to record aspects of the war. The family archive contains the catalogue from an exhibition by war artists during the conflict that lists five works by Zenzinger.
On April 19, three drawings by Zenzinger go under the hammer at Ludlow, Shropshire auctioneers Mullock's.
"Zenzinger was not a Nazi, and he was so appalled by what he witnessed during the Third Reich and the consequences of Hitler's actions that he attempted to erase his existence from history," explained Richard Westwood-Brookes, historical documents expert for Mullock's.
"He systematically went through the files removing any reference to his activities, and then locked up his entire collection of sketches, drawings and finished oil paintings in a warehouse in Austria, forbidding any but close friends and family from seeing it.
"He almost succeeded in his quest for anonymity, but a few references remained, largely in printed catalogues for Nazi art exhibitions staged during the War."
When the war ended, Zenzinger worked anonymously as a commercial artist in Vienna - his acquaintances were unaware of his wartime past.
He left his entire collection to his family who have continued to keep it concealed until now.
"In the hope that his achievements as a war artist will finally be recognised and the wartime record put straight, his surviving family have agreed to allow us to offer the first of what we hope will be many examples of his wartime art," explained Mr Westwood-Brookes.
"As I say, Zenzinger was no Nazi - in fact far from it. As a result, he concentrated on depicting the war from the perspective of the ordinary German soldier - he even ensured that in his pictures the Nazi emblems and regalia were concealed as much as he possibly could. As a result, in stark contrast to the sort of art which is often associated with the Nazi regime - of an idealised Aryan super race who were conquering the world under Hitler's evil doctrines - Zenzinger portrayed the ordinary soldiers going about their tasks under orders in much the same way as any soldier from Allied nations - and probably hating the War just as much."
Evidence of Zenzinger's personal animosity towards the Nazis emerged in the latter stages of the War, his art showing in stark reality what they had achieved - millions dead, destroyed cities and decimated population.
"I have seen some of the images from this later work and hopefully the family will feel able to release it on the market at a later date, as Zenzinger's pictures certainly stand as historical documents from a different perspective to those we are used to," said Mr Westwood-Brookes.
Mullock's initial offering is three pencil drawings by Zenzinger, each showing ordinary German soldiers in the midst of war. The first shows a soldier trying to fix his motor cycle side car in an alpine location, the second shows a soldier full length, with a stick grenade slung in his belt, while the third, pictured here, shows a grenade thrower about to launch his missile into the air.
"This will provide a unique opportunity to obtain work by a hitherto unknown artist whose importance will doubtless grow as more information emerges about him," added Mr Westwood-Brookes.
Each drawing is expected to make £3000.
By Ivan Macquisten