The spiders have been discovered at the northern plant in Umea, 640km north of Stockholm - apparenlty arriving with shipments of truck cabins made in Brazil, reports said Tuesday.
The biggest spider found so far was eight centimetres across, an employee a told Vasterbottens-Kuriren nesspaper, adding: "It was not a Swedish spider." Some of the creatures moved "incredibly fast".
No one has been bitten, the reports said - but management has now ordered that the cabins first be sprayed with water before assembly work goes ahead.