080408mko.jpgThe NYPD may have closed their probe into Heath Ledger’s fatal overdose, but federal investigators are still looking into the case. Or trying to look in, anyway – the Post reports that Mary-Kate Olsen is refusing to speak with investigators. Olsen, who was the first person called when her masseuse found Ledger’s body last January, is seeking immunity from prosecution in exchange for talking to the feds. DEA investigators are particularly interested in determining the source of Ledger’s OxyContin, for which he did not have a prescription. The Post has it that Olsen may be subpoenaed; sources say the DEA also had to threaten to subpoena the NYPD to get the department to hand over their Ledger files.

UPDATE:
Everybody listen up! Mary-Kate Olsen has just issued a statement:

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.

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.

We don't know the source of the information being quoted in the media regarding the Government's inquiry, but these descriptions are incomplete and inaccurate.

Confusing matters further, earlier today WNBC reported, contrary to the Post article, that Olsen has already been issued a subpoena.