Henryk Mandelbaum, who was forced by the Nazis to strip fellow Jews of valuables and gold teeth after they were gassed at Auschwitz, has died aged 85.

Mandelbaum died at a hospital in the southern Polish city of Bytom several days after undergoing heart surgery, said Igor Bartosik, a historian at the Auschwitz-Birkenau museum who has co-written an upcoming book on Mandelbaum. Bartosik said he did not know the exact cause of death, and hospital officials refused to comment.

Mandelbaum was Poland's last surviving member of a Sonderkommando - groups of Jewish prisoners forced to handle the bodies of fellow Jews who were gassed and burned. Mandelbaum was forced as a prisoner to strip victims' bodies of their valuables, pull out their gold teeth and fillings and carry them to crematoria for burning.

"When my group was taken the first day to work, the gas chamber was filled with dead people," Mandelbaum recalled later. He was forced to do the work from his arrival in Auschwitz, aged 21, on April 10, 1944, until January 1945, when the Nazis forced him and other fit inmates on a death march to flee the advancing Red Army.

"He saw people going into the changing rooms, he saw people changing, he saw the moment of the gassing, the throwing of the Zyklon B gas into the gas chambers, he heard the screams," said Bartosik.

Mandelbaum - inmate number 181970 - saw everything from beginning to end, Bartosik said. "They were treated as the bearers of a secret, people who were hardly there."

Mandelbaum was born in the southern Polish town of Olkusz. As the eldest of four children, he went to work in a quarry to support the family when his father's business became bankrupt. He developed physical strength that helped him pass an initial selection at Auschwitz, separating those capable of work from those who were sent immediately to the gas chambers.

Mandelbaum spent decades trying to teach younger generations about what happened during the Holocaust. He gave guided tours of Auschwitz and spoke frequently to groups about his experience.

"He tried to teach people that ... all people should respect each other, like each other, work together, and even if they have conflicts among each other, to end them. Life is too short to live in conflict," Bartosik said.

Mandelbaum found himself in the spotlight in May 2006, when Pope Benedict XVI visited Auschwitz. The Pope met 32 camp survivors, stopped to speak to each one, and kissed Mandelbaum - the only Jewish survivor in the group - on both cheeks.

Mandelbaum's parents, along with a brother and sister, were killed in the Holocaust. He is survived by his wife, a sister, one son and grandchildren.