25-year-old Mara seriously injured her shoulder, according to the Aftonbladet daily, while preparing for the role of Salander in the Hollywood version of the first of Larsson's Millennium trilogy books.
Filming has now been delayed for several days while the actress works to recover from her injury sustained while training for the role.
Mara has been in Stockholm for several weeks preparing for the task of playing the gothic hacker heroine Salander, including learning to ride a motorbike, fight and to build up her muscle strength. She has furthermore been undergoing classes to learn how to speak English with a Swedish accent.
Mara has been spotted undergoing rehab training at the private Sophiahemmet hospital in Stockholm to recover from her unfortunate mishap, according to Aftonbladet.
"She injured herself during the preparations for the role so seriously that she is unable to record any scenes at the moment," said an unnamed person who had seen the actress at the hospital to the newspaper.
However, Malte Forssell, the project leader for filming in Sweden told the newspaper he had no knowledge of the injury. In addition, a representative for Sony Pictures told US entertainment programme Access Hollywood that the reports of Mara's injury were "not true".
The US film team have identified a number of locations around central-eastern Sweden for the film. Södermalm on Stockholm will featured strongly, with the production using Mariatorget as a base.
Among other locations earmarked for scenes in the film are Uppsala, Katrineholm, Segersta near Bollnäs, with also Gävle and Söderhamn mentioned as possibilities.