Even in death, Osama bin Laden is the most wanted man on the planet -- at least to one undersea treasure hunter ... who's determined to find out once and for all if Osama is really dead.
Treasure-hunting explorer Bill Warren tells TMZ, the purpose of the excursion "is to try to find out if [Osama] is really dead and to provide to the world the proof that he is ... We do this because we are patriotic Americans and feel that President Obama failed to provide the proof."
Bill adds, "I do not trust my government or Obama."
Bill tells us, he's using several boats and top of the line technology to perform the search -- and the entire operation will cost hundreds of thousands of dollars.
Good news for conspiracy theorists -- Bill plans to take a film crew along for the ride and document the whole the trip.