Mary Kate Olsen refuses co-operate with investigators probing Heath Ledger's Death

New York, Aug 4 (ANI): Hollywood actress Mary Kate Olsen has refused to help the federal investigators probing Heath Ledger's strange accidental drug death unless she receives immunity from the prosecution.

Apparently, it was Olsen who was the first one to be informed of Heath's death after her masseuse discovered the actor's body in his Soho apartment.

Ledger, whose role as the joker in 'The Dark Knight' may bag a posthumous award, died of a cocktail of drugs and oxycontin, the latter of which was likely obtained illegally.

"Everyone has been very eager to help, saying what a great guy Heath Ledger was, everyone except Mary-Kate, who has refused to speak," the New York Post quoted a source as saying.

"Ms. Williams was extremely nice and cooperative," the source added.

It has been revealed that the investigators are trying their best to find the source of Oxycotin, and whether it came from a dealer or a friend.

Everybody including the actor's helpers, masseuse and even friends and the mother of his daughter actress Michelle Williams have been examined by the investigator.However Olsen the final witness needed to conclude the investigation has not yet co-operated with the investigators. (ANI)