Though Mary-Kate Olsen wants to stay quiet about Heath Ledger's death, the feds may not let her off the hook.
Apparently, Miss O. is refusing to let federal investigators interview her regarding Heath's drug overdose... unless they grant her immunity from prosecution.
Sounds fishy, right? Why else would she want immunity unless she's done something wrong?
For those of you who need a reminder of Mary-Kate's connection to all this in the first place: Michelle Tanner was the first person the masseuse called after finding Heath's body.
Do you think Mary-Kate is hiding something?