The iron sign, which was stolen from the entrance to a Nazi-era concentration camp in Poland, may return to the Auschwitz-Birkenau museum on December 22, the museum's spokesman told RIA Novosti on Monday.

The sign, which is German for "Work Sets You Free," disappeared between 4 a.m. and 5 a.m. local time last Friday. Workers of the memorial, which is located at the former camp, put at the entrance the sign's copy made during renovation work in 2006.

The infamous sign was found in a small town in northern Poland, it was sawn into three parts, each containing one word. Police detained five suspects, all of them men aged from 20 to 39.

The spokesman said he did not know how much time the sign's restoration will take.

"I believe that it will be possible to reinstall the sign before the 65th anniversary of the concentration camp's liberation by Soviet troops - January 27, 2010," he said adding that security measures at Auschwitz will be tightened after the incident.

Police said the sign was stolen for "a crazy collector."

Auschwitz-Birkenau was the largest of all the concentration and extermination camps operated by the Nazis during World War II. More than 1 million people - 90% of them Jews - died there.

WARSAW, December 21 (RIA Novosti)