To the deniers: are you saying that the U.S GIs who liberated Dachau are/were liars?
Not all of those in the camps were gassed. Some were shot, some died of disease, some of starvation.
Not all of those in the camps were jewish. The original prisoners were political enemies. Afterward some were gypsies, homosexuals, the physically and mentally disabled, etc.
I don't believe we will ever know the true numbers because not all of the bodies were discovered.