Saudi Defense Minister Prince Sultan bin Abdul Aziz and Prince Turki al-Faisal, formerly head of Saudi Arabia's intelligence agency, have been sued by hundreds of relatives of the victims. They allege the two knowingly contributed money and support to al-Qaida through Islamic charitable organizations.
The $1 trillion lawsuit says members of the Saudi royal family paid protection money to Osama bin Laden's group to keep it from carrying out terror attacks in Saudi Arabia.
A federal judge is expected to rule soon, perhaps next week, on whether the men are immune from the civil suits.
At issue is whether U.S. courts have jurisdiction over the two princes in light of the Foreign Service Immunity Act.
Bill Jeffriss, representing Prince Sultan, said the contributions made to Islamic charities that may have funneled money to bin Laden amount to "an exercise by a foreign official of discretion to decide which international Islamic charity and what relief operations by Islamic organizations the country's going to support."
"It's a core government function and not something a public official can be hauled into court for," Jeffriss said.