Lawyers for Mary-Kate Olsen say the actress had nothing to with prescription drugs found near Heath Ledger's body following the Australian star's death from an accidental overdose earlier this year.
A statement from her lawyer says former child star Olsen co-operated with investigators probing the source of drugs involved in Ledger's death.
It follows recent tabloid reports that Olsen had demanded immunity from prosecution in exchange for co-operating with investigators.
But the statment says Olsen, a close friend of Ledger, had no knowledge of the drugs he consumed or those found in his apartment.
"Despite tabloid speculation, Mary-Kate Olsen had nothing whatsoever to do with the drugs found in Heath Ledger's home or his body, and she does not know where he obtained them," Lawyer Michael Miller said.
"Regarding the government's investigation, at Ms Olsen's request, we have provided the government with relevant information including facts in the chronology of events surrounding Mr Ledger's death and the fact that Ms Olsen does not know the source of the drugs Mr Ledger consumed.
