A court in the southern Polish city of Krakow, where Anders Högström is being questioned, ordered him on Friday to stay behind bars for at least three more months, Poland’s PAP news agency reported.
Högström, 34, was extradited to Poland from Sweden last week, two months after being arrested in his homeland on a Polish warrant. He risks 10 years in prison if convicted.
On Monday, Krakow prosecutors said Högström had denied plotting the December 18 theft of the gateway sign from the site of the camp in the southern Polish city of Oswiecim, which has became a notorious symbol of genocide by the occupying Nazi Germans.
Polish police recovered the five-metre metal sign — which means “Work Will Set You Free” in German — on December 20.
They arrested and charged five Polish men, three of whom, considered relatively small fry, have already been sentenced to two-and-a-half years in prison.
The two others, suspected of playing a far more prominent role in the theft, are to be tried after Högström has been questioned.
In 1994, Högström founded the National Socialist Front, a Swedish neo-Nazi movement he headed for five years before quitting.
He has told Swedish media he was to act as an intermediary to pick up the sign and sell it to a buyer, adding however that he informed Polish police about the people behind the plot.
The sign, which had been cut into three parts, was returned by investigators to the Polish state-run Auschwitz museum on January 21, less than a week before commemorations for the 65th anniversary of the camp’s liberation by Soviet troops.
One million of the six million Jews who perished in the Holocaust were murdered there, mostly in the camp’s notorious gas chambers, as well as tens of thousands of others including Poles, Roma and Soviet prisoners of war.