@call1n, you're sick in the head.
Before 1989 the reported total figure of deaths at Auschwitz was 4 million.
That was the Soviet Union estimate. The Nazis destroyed most of the documentation, so it wasn't known how many exactly people were murdered. The Soviet committee made a mathematical estimate - they took into consideration the number of days and the capacity of crematoria. According to the report of Witold Pilecki, who was a prisoner of Auschwitz-Birkenau camp himself, it could be from 2 million to 5 million people.
A quote from Wikipedia (my translation from Polish):
"When I went out from Auschwitz (27.04.1943) 97 000 prisoners with tattooed numbers were murdered. That number had nothing to do with with the number of
undocumented people who were being gassed and burned by their masses. Over two million of them were killed. I've given those numbers roughly in order not to exaggerate. My colleagues, who were prisoners for longer than me and witnessed 8000 people being gassed a day, give the estimate of 5 million people."
So, the problem was that up to 80% people who were sent to Auschwitz-Birkenau camp didn't get to be prisoners - after arrival at the camp they were sent straight to gas chambers and burnt. Those were Jews from Poland and all over Europe.
So, there was even no bodies that you could count after the camp was liberated.
As you can see - those higher numbers weren't due to some kind of ill will or intent to fool people. Over the years due to historical research those numbers were simply verified.