Have you ever wondered what became of Osama Bin Laden’s trust fund?

Coming up Friday in a federal courtroom in lower Manhattan is a hearing that could mark a turning point in attempts to solve the mysteries that by some accounts still shroud the fate of the multi-million dollar inheritance of Osama bin Laden. This hearing, before U.S. Magistrate Judge Frank Maas, is part of the 9/11 civil suits brought by families and colleagues of some of those murdered in Al Qaeda’s Sept. 11 terrorist assaults on America (”In re: Terrorist Attacks on September 11, 2001″).

The immediate issue involves dreary-sounding matters of jurisdiction. But that leads on to the big question of whether more documentation out of places such as Saudi Arabia might become available — possibly providing more insight into the exact fate of Osama’s inheritance.

But wait a minute, wasn’t that all settled by the 9/11 Commission? — which reported in 2004 that Osama’s share of the Bin Laden family business was sold in 1994, and the Saudi government “subsequently froze the proceeds of the sale.”

Well, there are some questions still unanswered, according to a fascinating and heavily researched new book, just out, “The Bin Ladens: An Arabian Family in the American Century,” by Pulitzer Prize-winning author Steve Coll. On pages 405-408, Coll delves into the story of Osama’s inheritance, and comes up with a load of questions. Based in part of court documents that have already floated up in the 9/11 cases, Coll writes that in June, 1993, the Bin Laden family began the process of expelling Osama as a shareholder from two family companies: the Mohamed Bin Laden Company, and the Saudi Bin Laden Group. By 1994, says Coll, Osama’s shares had been sold “in a transaction designed so that Osama would not profit, yet in a way that would protect the rights of his heirs under Islamic law.” The value was set at about $9.9 million — “a strikingly modest sum,” but hard to judge “because few of the underlying assumptions used to set the price are available.” The tale proceeds: “After consultations with the Saudi government, the funds generated by the sale of Osama’s shares were placed in some kind of special trust and eventually frozen under court supervision.”

But is that all there was to it? As Coll tells it, Osama assigned his shares in 1993 to one of his brothers, Ghalib Bin Laden. Coll writes that later that same year, 1993, Ghalib Bin Laden “transferred $1 million to a new investment account at Bank Al-Taqwa, in the Bahamas, an off-shore bank founded in 1988 with backing from the Egyptian Muslim Brotherhood.” Ghalib’s account at Al Taqwa, over which yet another Bin Laden brother, Bakr Bin Laden, had signature authority, remained active “until at least the late 1990s,” according to bank documents filed in a U.S. court, writes Coll. [Note: In November, 2001, the U.S. Treasury designated Al Taqwa as an Al Qaeda-linked financier of terror; it remains under that designation today.]

The Bin Laden clan denies any wrong-doing. Bakr Bin Laden, in an affidavit, has said that since Osama was cut off, at the latest in June, 1993, “Osama has not received a penny,” and that since that date anyone acting on behalf of the Bin Laden companies was forbidden to make any payments to Osama, or provide any support, direct or indirect.

Coll tries to fill in more details, and bumps up against assorted mysteries, writing: “A number of aspects of Osama’s shareholding divestment remains unclear, however. For example, it is uncertain whether Ghalib paid cash for Osama’s shares, and if so, where he raised the money from.”

And here come Coll’s questions:

“Is there a bank account in Saudi Arabia that has held the $9.9 million in trust ever since the sale was completed? How do Saudi courts assert control over such an account, if it exists? If the sale did not involve a cash payment, but rather a credit of some kind, how was this organized and who has kept track of the proceeds since then?” He concludes: “The Bin Laden family has provided little clarity about these details.”

Which brings us to the hearing this Friday in lower Manhattan, where families and colleagues bringing suit over the September 11 attacks will be waiting to find out whether answers to some of these questions might yet emerge. I’m curious myself, and plan to tear myself away from Steve Coll’s book long enough to drop by the courtroom to witness this next scene, live, in this long-running drama of our times.