[From the article "Western Holocaust camps"]

Holocaust revisionists argue that catastrophic conditions in Germany at the end of the war (caused by factors such Allied bombing of German infrastructure) caused large scale epidemics and malnutrition in many camps (and elsewhere in Germany). American and British forces arrived at western camps located in western Germany at the end of the war in 1945. Soon photographs and movies showing scenes due to starvation and epidemics were widely shown and framed as showing German mass killings. Allied psychological warfare units are argued to have played important parts in creating this impression. See also the article on Holocaust documentary evidence and the section "Photographs of heaps of corpses and emaciation" and "Movies" on these widely published photographs and movies from the Western Holocaust camps.

Allied propaganda had long before this claimed mass killings in camps and the Soviets had already in 1944 reached the Majdanek camp and used it for propaganda claims of German mass killings (somewhat later other camps in Poland and eastern Germany were used similarly). However, the false propaganda claims used by the Allies during the First World War against Germany were widely known and many distrusted Communist propaganda. Thus, the photographs and movies from the western camps were likely influential in convincing many that the politically correct view on the Holocaust was correct and not just wartime propaganda. Later, after German mass gassings/killings had become an established Truth, many of the early claims regarding the western camps were abandoned.

[...]

While many of the early claims regarding the western camps have been abandoned, there are still contradictory "mainstream" views on the presence of some homicidal gas chambers and some experimental/comparatively small scale gassings in some of the western camps. Some mainstream sources reject this, other support this, with some claims alleging thousands of gas victims. In the museums of several of the former camps there are sites where homicidal gas chambers are alleged to have been located. In Dachau an alleged homicidal gas chamber is even shown in its alleged original condition (see below).

On the other hand, there is a consensus that earlier allegations of gas chambers/gas chambers killings in some camps, such as in Buchenwald and Bergen-Belsen, were false, despite earlier being supported by "witnesses" and "confessors".

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The revisionist Jürgen Graf has written that "Some of the camps continued operation after the war, this time with allied personnel and German prisoners who were considered a threat to allied security or who were opposed to occupational policies. Especially infamous in this regard is the Sachenshausen camp under Soviet control, but even the American operated Dachau camp served as a concentration camp after the war. One of the prisoners held captive by the Americans in Dachau published a diary, which is interesting reading especially when compared with the diary of a prisoner who was in the same camp under German rule, i.e., during the war. In an analysis, Ingrid Weckert has juxtaposed both diaries and by so doing, was able to show that conditions in the Dachau camp were considerably better under German rule than they were under U.S. military rule – except for the very last months of the war, when the German infrastructure had broken down and the inmates, like everybody in Germany, suffered terribly due to lack of all supplies."