Washington- A convicted al Qaeda terrorist has claimed that the Saudi Arabia royal family was involved in the 9/11 terror attacks in the United States, while the Saudi government has denied the allegations.

The testimony was given by French national Zacarias Moussaoui in October last year, as part of an ongoing civil case filed by the families of 9/11 victims, against the Kingdom of Saudi Arabia for its alleged involvement.

Moussaoui, who is currently in prison for terror related charges in Colorado, has alleged that he even attended a meeting in the Saudi Embassy in Washington, to discuss a terror attack on US President's aircraft Air Force One.

He added that the discussion even included, use of Stinger missile for the attack. He even claimed that the terror group had entrusted him, with the responsibility of creating a digital database with names of donors.

Of these, there were several high-profile names including that of Prince Turki al-Faisal Al Saud, former director-general of Saudi Arabia's foreign intelligence service and Ambassador to the United States, who also introduced him to members of other Saudi royal family, the CNN reported.

The 46-year-old alleged that he acted as a courier, between slain terrorist Osama bin Laden and the royal family of Saudi Arabia. Moussaoui said that he even met the Saudi royals and delivered letters to and from Osama.

Meanwhile, Saudi Arabia has rejected the allegations made by Moussaoui. A statement issued by them stated that the national September 11 commission in 2004 had already rejected the claims, and found no involvement of Saudi government.

"Moussaoui is a deranged criminal whose own lawyers presented evidence that he was mentally incompetent. His words have no credibility," the statement said, the CNN reported.

"Moussaoui's goal in making these statements only serves to get attention for himself and try to do what he could not do through acts of terrorism to undermine Saudi-US Relations."