Huh? The scarily thinner Olsen twin is demanding that police grant her immunity from any charges before she’ll talk to them about the tragic death of Heath Ledger:

Actress Mary-Kate Olsen has refused to answer questions from federal authorities investigating the accidental overdose that killed actor Heath Ledger until she receives immunity from prosecution, The New York Post reported.

The former child-star, famous for playing Michelle Tanner on “Full House,” was a close friend of Ledger’s and the first person called after her masseuse discovered Ledger’s body in his Soho apartment in January, The Post said.

But federal officials could force the actress to tell them details on the “Dark Knight” star’s drug use and events leading up to his death if they obtain a grand-jury subpoena.

One source told The Post that “everyone has been very eager to help, saying what a great guy Heath was, everyone except Mary-Kate, who has refused to speak.”

When Olsen got the call that Ledger — whose performance as the Joker in “The Dark Knight” has earned rave reviews — was dead, she reportedly failed to call authorities, and instead telephoned her body guards. According to The Post, they arrived just as paramedics got to the scene.

Ledger’s death was ruled an accidental drug overdose by medical examiners, caused by a combination of prescription drugs and the pain reliever OxyContin. According to The Post, the latter was likely received illegally.

Looks like America’s former sweetheart isn’t just using (as unconfirmed rumors claim) but maybe doing a little dealing on the side. Either that or she’s the kind of drug-addicted moron who hands out pain killers to her friends without a care in the world.

Is there a cover-up being orchestrated? The Post seems indicate that the feds think so and were not happy with the NYPD’s decision to let Olsen off the hook:

… And NYPD investigators closed their probe without interviewing Olsen because, they said, they got all the cooperation they needed from others. That decision, however, surprised some observers, considering Olsen’s role as a potential witness.

Instead of calling emergency responders after getting the call from her masseuse, Olsen telephoned her bodyguards in the Big Apple, telling them to race to Ledger’s Broome Street home, where they arrived just as paramedics got to the scene.

The US Drug Enforcement Administration, which opened an investigation to determine the sources of Ledger’s drugs, was not as sanguine as the NYPD about talking to the 4-foot-11, 90-pound Olsen.

The feds contacted her lawyer, Michael Miller, several times recently seeking her cooperation, but Miller has told the feds Olsen won’t be interviewed unless she gets immunity, exercising her constitutional rights.

According to sources, all of the drugs in Ledger’s body and discovered nearby in prescription bottles were legally obtained from two physicians – with the exception of OxyContin, a powerful painkiller.

Investigators “are trying to ID the source of the OxyContin,” a source said. “Did it come from a dealer, from a friend? If he had a bottle from a friend, was it taken by someone else before police responded? That is what is trying to be determined.”

The DEA probers were also aggressive with the NYPD, the sources said, and were forced to threaten to obtain a grand-jury subpoena before getting the department’s Ledger files.

An NYPD spokesman said the department never balked at handing over the files and did so after receiving a routine federal administrative subpoena.

Asked whether he asked for immunity for his client, Olsen’s lawyer said, “We are not going to comment on whether there is a criminal investigation,” and declined to speak further.

So it looks like Heath Ledger isn’t the only victim of the drug culture in this story. Olsen is clearly in some way involved in something which the feds will find out about. This is just another victimless crime though, right? Only Heath Ledger was hurt by his drug use, right? Not his child, not his family and certainly not Mary-Kate Olsen who’s quite possibly on her way to jail.

Though because she’s rich and a celebrity she won’t go to jail, but if it turns out she gave/sold the Oxycontin to Ledger that helped killed her friend she’ll have to live with that the rest of her life.