In 1656 he was unexpectedly arrested in the city of Elbląg by the Swedes and was imprisoned in the castle in Malbork. At the beginning of 1657 he was prosecuted for betraying the interests of Charles Gustav and imprisoned in the castle of Örebro in Sweden. This was primarily caused by Charles Gustav's worries that Radziejowski could be a spy for Poland and especially create tensions between the two countries to cause war that would decrease Sweden's power in the region. In 1660 he was released from captivity.