The disclosure has revived questions about the FBI’s investigation into what Saudi officials might have known about the hijackers inside the United States — evidence that the Trump administration has asserted is a “state secret” the disclosure of which could harm national security.

“I don't think the public has had the benefit of understanding the full linkages there,” said Figliuzzi, who served in the assistant director for counterintelligence role between 2010 to 2012. “The Saudi government is a force to be reckoned with in regard to their linkages to radical violent extremism, their funding of operations within the United States to include radical Muslim clerics ... their funding of madrassas or Muslim schools and even clerics that expound radicalism and extremism.”

Figliuzzi said the Saudi regime continues to fund extremist clerics, and called members of the Saudi intelligence service “stone cold killers,” pointing to the killing of Washington Post reporter Jamal Khashoggi.

Despite Saudi denials about the kingdom’s complicity in the 9/11 attacks, questions about a possible link have swirled for years. Fifteen of 19 hijackers killed on Sept. 11 were Saudi nationals; many in law enforcement have long suspected the Saudis knew more than they let on about the plot. Osama bin Laden, the now deceased longtime head of al-Qaida, is from a prominent Saudi family with major construction interests and strong ties to the regime.

The new disclosure about the possible role of a Saudi Embassy official emerged in a federal court filing by Jill Sanborn, the bureau’s current assistant director of the counterterrorism division, in response to a lawsuit brought by families of 9/11 victims that accuses the Saudi government of complicity in the terrorist attacks.