The group of seven men and four women carried out the unprecedented stunt on Friday.
The group of seven men and four women -- Poles, Belarussians and one German -- carried out the unprecedented stunt on Friday in front of the camp's infamous "Arbeit macht frei" ("Work makes you free") gate, where they draped a white banner with "love" written in red.
"We should do everything we can to stop war, to not allow new bloodshed," the group, which calls itself "Love Macht Frei", said in a statement published on the website of the Gazeta Wyborcza daily.
"By allowing military conflicts, humanity is unconsciously trying to open up a Pandora's box and lead the relative world order towards another bloodbath and mass terror."
The group said the slaughtered lamb was a "symbol of an innocent being who suffers for nothing".
Guards at the site in the southern Polish city of Oswiecim immediately intervened and police took in the individuals, aged between 20 and 27, for questioning.
On Saturday prosecutors charged them with "desecrating a monument". The man who killed the lamb faces additional charges under animal protection laws that carry a penalty of up to two years behind bars.
The museum located on the site of the former death camp said it was "shocked and outraged" by the stunt, while Poland's chief Rabbi Michael Schudrich said it was a "desecration of the memory of all those killed at Auschwitz".
Nazi Germany built the Auschwitz death camp after occupying Poland during World War II.
The Holocaust site has become a symbol of Nazi Germany's genocide of six million European Jews, one million of whom were killed at the camp between 1940 to 1945.
More than 100,000 non-Jews also died at the death camp, according to the museum. An estimated 232,000 of the victims were children.