The cars are believed to have been heading for a test track near the town of Arvidsjaur when the fire broke out in the truck’s rear axel, ten kilometres south of the town at 9am on Monday.
“There were six cars on the transporter, although I don’t know what model they were,” Arvidsjaur’s fire chief Urban Wikberg told The Local.
“The cars were not badly damaged, although there could have been some smoke damage,” he added.
Local police chief Mikael Norén was quoted by Expressen as saying that the owners of the cars “were not happy.”
“These are super-secret cars,” he said.
Many of the world’s top carmakers and component companies use the tracks in Arvidsjaur and other sites in northern Sweden for winter road testing of new models.
Among the companies that frequently use test tracks in northern Sweden are Daimler Chrysler, Ford, General Motors, Porsche and VW, as well as component makers including Bosch, Continental Teves and TRW Automotive.