The man has previously been convicted of bombing in Gothenburg almost three years ago. He was sentenced by the High Court to one year and ten months in prison for an explosive charge found at a campsite near a refugee residence. The bomb was found before it detonated.
The Security Police does not want to comment on whether it has cooperated with the Polish security service in this case.
"When it comes to our cooperation with other countries, it's not something we go into," Gabriel Wernstedt, press secretary at Säpo, tells TT.