Bodog Beat

Mary-Kate Olsen's lawyer has done a bang-up job of making her look guilty. (AP Images)

What do you do when you have nothing to hide? You don't do what Mary-Kate Olsen's lawyer has advised her to do — which is to refuse to speak to Feds and demand immunity.

Now, the DEA is convinced she's hiding something (duh) and have subpoenaed her ass to testify in front of a grand jury.

Basically, they want to know how Heath Ledger got his hands on the drugs that he overdosed on. And the fact that Olsen was called repeatedly when Ledger's body was found has raised their suspicions.

Mary-Kate's lawyer issued the following 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."

Access Hollywood, who broke the story, have consulted a lawyer who says that demanding immunity is a cautious way to proceed and does not imply guilt.

So far, there is no word as to when Olsen might be called to testify.