Is Mary-Kate Hiding Something?

Though Mary-Kate Olsen wants to stay quiet about Heath Ledger's death, the feds may not let her off the hook. Apparently, Mary-Kate is refusing to let federal investigators interview her regarding Heath's drug overdose... unless they grant her immunity from prosecution.

Why would she want immunity unless she's done something wrong?

Mary-Kate's connection to all this in the first place: Mary-Kate was the first person the masseuse called after finding Heath's body. 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.

His death was ruled an accidental drug overdose by the medical examiner. 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."

Could Mary-Kate be the dealer behind those two mysterious drugs?

Source