Mary-Kate Olsen Denies Supplying Ledger Drugs
Olsen Seeks Immunity From Prosecution Over Heath Ledgers death
Olsen was the first person contacted by the masseuse who discovered Ledger's body, she was contacted three times before 911 was dialled and once afterwards.
The Drug Enforcement Administration want to question Olsen about how Ledger obtained two powerful prescription painkillers that contributed to his death.
Olsen's lawyer, Michael C Miller, claims that Mary-Kate "does not know the source of the drugs Mr Ledger consumed".
An official, who has anonymity as the investigation is ongoing, says that authorities had obtained a subpoena that could force Olsen to appear before a grand jury if she fails to comply.
Other potential witnesses, such as doctors and Ledger's ex-girlfriend Michelle Williams, all have answered questions voluntarily.