In a 2009, report released by the Senate Committee on Foreign Relations about the U.S. failure to capture bin Laden earlier, says the will is "regarded as authentic."
Calls to the committee asking for how the document was authenticated were not immediately returned.
But for the man who first raised the alarm about al Qaeda and hunted bin Laden in the days following 9/11, the document is an obvious fraud.
"It's a Saudi fabrication and it's been around for years," said Michael Scheuer, a veteran CIA agent who headed the secretive Bin Laden Issue Station, nicknamed Alec Station, and was later the chief of the bin Laden Unit.
"Nothing in it resembles bin Laden's thought patterns," he said. "The structure of the language is all wrong. One thing that never appears in his documents is despair, and this thing is full of despair."
"It's a direct contradiction to what we know about bin Laden," he said.