Mary Kate Olsen has refused to answer questions from Drug Enforcement Agency - the agency which is probing Heath ledger's death. The actress, being the first to hear about the actors death from his masseuse, is the immediate focus of the investigation. But she refuses to let the cat out of the bag without immunity from the prosecution. Her lawyer Michael C Miller claims that she has nothing to with the drugs that the actor dies under the influence of. Olsen's party has furnished all the information required by the investigating authorities that was required of them and has categorically stated that the Olsen twin has no knowledge of any drug related activity that could have spurned the actors sudden death.