COPENHAGEN, Denmark — The investigation into how an iron gate stolen from the Nazis' Dachau concentration camp in southern Germany ended up in western Norway may be complicated because "no useable evidence" has been found, police said Saturday.

Police spokeswoman Kari Bjoerkhaug Trones says the gate with the cynical slogan "Arbeit macht frei" — "Work sets you free" — was found Nov. 28 under a tarpaulin at a parking lot in Ytre Arna, a settlement north of Bergen, Norway's second-largest city.

Police Attorney Kari Bjoerkhaug Trones is pictured on Dec. 3, 2016 in Bergen, Norway, beside the iron gate from the former Nazi concentration camp in Dachau, southern Germany, with the slogan "Arbeit macht frei" ("Work will set you free"), found by the police in Bergen this week, two years after it had been stolen. MARIT HOMMEDAL / AFP - Getty Images

"It has been there for quite some time with some junk under a tarpaulin. Our forensic teams have found no useable evidence like DNA," Bjoerkhaug Trones told The Associated Press. The gate was now in police care, she said, adding they have no suspects.

The concentration camp near Munich was established by the Nazis in 1933. The missing gate, measuring 190 by 95 centimeters (75 by 37 inches), originally was set into a larger gate at the camp's entrance.

More than 200,000 people from across Europe were held at Dachau, and more than 40,000 prisoners died there.

The camp was turned into a memorial site, and the gate's theft in November 2014 was viewed as a desecration. The Dachau memorial's director described the gate as "the central symbol for the prisoners' ordeal." Israel's Yad Vashem memorial labeled the theft as "an offensive attack on the memory of the Holocaust."

Jean-Michel Thomas, president of the International Dachau Committee that represents former prisoners, survivors and victims from Dachau, was "very happy" with the recovery of the gate.

A replica was installed in the missing gate's place last year as part of events marking the 70th anniversary of the liberation of the camp by U.S. forces in April 1945.