The arrest took place “during the afternoon in Stockholm, at his home,” prosecutor Agneta Hilding Qvarnström told AFP.
“He is currently held at the police station and he has asked for a lawyer, which we are trying to get him,” she added.
Hilding Qvarnstroem would not detail the charges brought against Högström.
She said a Stockholm court would decide whether to extradite him.
The prosecutor on Wednesday had instructed Swedish police to arrest Högström, 34.
Poland issued a European arrest warrant for Högström on February 2nd, after Sweden provided additional information on the suspect’s place of birth, parents’ names and residence.
Polish justice authorities indicted Högström in January for his alleged involvement in the December 18th theft of the sign from the gate of the notorious camp set up in occupied Poland by Nazi Germany during World War II.
Högström has told Swedish media 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 on January 8th.
“We had a person who was willing to pay several million (kronor, or hundreds of thousands of dollars/euros) for the sign,” he said.
Polish police recovered the five-metre (16-foot) metal sign, whose German inscription means “Work Will Set You Free” in English, on December 20th, two days after the theft, and arrested and charged five Polish men.
The sign, which had been cut into three parts, was returned by investigators to the Auschwitz museum on January 21st, less than a week before commemorations marking the 65th anniversary of the camp’s liberation by Soviet troops.
Högström in 1994 founded the National Socialist Front, a Swedish neo-Nazi movement he headed for five years before quitting.
He had claimed he helped police nab the people behind the theft, telling Aftonbladet, “I’m proud to have revealed everything.”
But a Krakow police spokeswoman denied at the time that he had played any role in helping police.
“The phone call from Sweden came as we were already in the process of arresting the thieves,” she said.
The sign has long symbolised the horror of the camp where some 1.1 million people — one million of them Jews — fell victim to Nazi German genocide from 1940 to 1945.