Williams and Ledger had split up shortly before Ledger died in January of an accidental prescription drug overdose at the age of 28; however, the pair reportedly remained close until his death and Williams has since spoken fondly of her former beau to the media.
The Australian actor has been posthumously winning and been nominated for awards in recent weeks for his stunning portrayal of the Joker in "The Dark Knight."
Rumors have been swirling regarding who might pick up his Oscar and other awards, if he wins them, with various reports saying his parents and sister, co-stars and Williams will do the honors.
However, Williams' publicist told TMZ, "No discussions have been made for Michelle to accept nor are there any plans to take part."
NBC reportedly holds celebs hostage to Jimmy Fallon's show
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