As per Reuters:
"A document circulating on the internet purporting to be a crisis plan for Mt. Gox, said more than 744,000 bitcoins were "missing due to malleability-related theft" and noted Mt. Gox had $174 million in liabilities against $32.75 million in assets. It was not possible to verify the document. If accurate, though, it would mean about 6 percent of the 12.4 million bitcoins minted would be considered missing."