Iranian officials knew in advance about the Sept. 11 terrorist attacks and was involved in the planning, according to the testimony of two defectors from the Islamic regime's intelligence service in a federal lawsuit, The New York Times reported Friday.

According to a court filing Thursday cited by the newspaper, the suit is seeking damages for Iran's "direct support for, and sponsorship of, the most deadly act of terrorism in American history."

One of the defectors claims that Iran and Hezbollah, the radical militant group in Lebanon, played a role in plotting the attacks, orchestrating the hijackers' training and travel and helped Al Qaeda operatives escape after the attack, providing some with refuge in Iran.

The possible link between Iran and 9/11 has been long debated since the national 9/11 commission said in its report that there was "strong evidence that Iran facilitated the transit of Al Qaeda members into and out of Afghanistan before 9/11, and that some of these were future 9/11 hijackers."

Intelligence officials also believe Al Qaeda and Iran are in cahoots, albeit in limited fashion, against the U.S., the newspaper said.

Attorneys representing the families are seeking a default judgment against the defendants, including Iranian officials and ministries, Hezbollah and Al Qaeda, who are not putting up a defense. Legal experts told the newspaper that even if such a judgment were awarded, it would be difficult to collect monetary damages.