Polish police say the infamous iron sign over the gate to the Auschwitz memorial site with the cynical phrase "Arbeit Macht Frei" _ German for "Work Sets You Free" _ has been stolen.

Police spokeswoman Katarzyna Padlo said police believe it was stolen between 3:30 a.m. and 5 a.m. Friday, when museum guards noticed that it was missing and alerted police.

Padlo says the iron sign, which spanned a gate at the main entrance to the former Nazi death camp in southern Poland, was removed by being unscrewed on one side and pulled off on the other.

She says police have launched an intensive search. She says there are currently no suspects but police are pursuing several theories.