“We have indicted Anders H. with incitement to theft,” spokeswoman for Krakow regional prosecutor Boguslawa Marcinkowska told Poland’s TVN24 news channel.
Polish prosecutors also requested a Polish court to order that the suspect, identified by media as former Swedish neo-Nazi Anders Högström, 34, to be provisionally detained for 14 days.
Prosecutors intend to issue national and subsequently European arrest warrants for the man as soon as the court approves the arrest order, Marcinkowska said.
Anders Högström, 34, a former Swedish neo-Nazi, has said he was supposed to act as an intermediary to pick up the sign and sell it to a buyer, but in the end he wound up informing Polish police about the people behind the plot.
“I was asked if I wanted to take the sign from one location to another,” he told tabloid Aftonbladet.
“We had a person who was willing to pay several millions (of kronor, or hundreds of thousands of dollars) for the sign,” he said.
He claimed he helped police nab the people behind the December 18 theft.
Police recovered the five-metre metal sign — which means “Work Will Set You Free” in German — on December 20 in northern Poland and arrested the five Polish men.
The sign had been cut in three parts.
“I’m proud to have revealed everything,” Högstroem said.
But questioned by AFP, a Kracow police spokeswoman denied he played a role helping police catch five Poles, aged 20 to 39, suspected of physically stealing the sign.
“The phone call from Sweden came as we were already in the process of arresting the thieves,” she said.
The five suspects face up to 10 years behind bars if found guilty of the theft from the UNESCO World Heritage site as charged.
In 1994 Högström founded the National Socialist Front, a Swedish neo-Nazi movement he headed for five years before quitting.
After leaving his party, he distanced himself from the movement and became a model citizen, joining an association called Exit which helps youths quit far-right movements, Aftonbladet claimed.
The National Socialist Front was dissolved in late 2008.
The sign above Auschwitz’s gateway has long symbolized the horror of the camp where some 1.1 million people, mostly European Jews, fell victim to Nazi German genocide.
The Nazis created the camp in occupied Poland in 1940. It was in operation until Soviet troops liberated it in 1945.