Experts cast doubt on Moussaoui's credibility, as he is erratic in court

Government lawyers interviewed him and said he had 'relevant' material

He said an unnamed prince paid for him and 19 hijackers to learn to fly

Claims: Zacarias Moussaoui, who is serving a life sentence for terror charges, has said Saudi Arabia financed the 9/11 attacks

A jihadist serving life in prison on terror charges brought in the wake of 9/11 has claimed the Saudi Arabian royal family helped finance the plot.

Zacarias Moussaoui, 46, says an unnamed Saudi Prince paid for flying lessons for him and the 19 terrorists who hijacked planes in the September 11 attacks in the run-up to the atrocities.

The incredible claims were made in documents filed to a federal court in Oklahoma, in which Moussaoui says a prince 'was assisting me in my Islamic terrorist activities... and was doing so knowingly for Osama bin Laden'.

He also said that bin Laden provided assistance from Saudi leaders in planning the attacks, and that he was involved in a plot to shoot down Air Force One with President Bill Clinton on board.

The Saudi government has flatly denied any involvement in 9/11. Moussaoui's own credibility is also suspect - as even Osama bin Laden has denied he had anything to do with his terrorist plots.

Lawyers for the Federal government have taken him seriously enough to interview him over the claims at the maximum security Colorado prison where he is serving a life sentence without parole. They say he had 'relevant' material to contribute.

However, officials in Oklahoma have said Moussaoui's requests to be allowed to speak in open court and to be assigned government lawyers will probably be denied, as his claims have nothing to do with any existing cases.

'Even if he somehow got to the point where he could testify, there would be a credibility issue,' said Carl Tobias, a professor at the University of Richmond School of Law. 'Would his testimony be valuable? That's doubtful.'

Court battles: Moussaoui cut a bizarre figure in his three-year-long trial on terror charges. Above, a court sketch shows him celebrating as he is sentenced to life in a maximum security prison

The offers are also clouded by his record of changing his account of his involvement in the Sept. 11 plot and his erratic behavior in court.

In court papers filed in Manhattan in September, lawyers for Saudi Arabia said flatly: 'The Kingdom of Saudi Arabia had no role in the attacks of September 11, 2001.' They also noted that the United States 'has said often and vigorously that Saudi Arabia is an important ally in the fight against terrorism.'

Even so, his attempts to cooperate in the civil cases stand in contrast to the defiant attitudes of other al-Qaida defendants who have endured after years of confinement without volunteering information except for claims they were tortured.

Moussaoui, who is 46 and refers to himself in writing as 'Slave of Allah,' was first arrested on immigration charges in August 2001 after employees of a Minnesota flight school became alarmed that he wanted to learn to fly a Boeing 747 - even though he had no pilot's license.

Atrocity: According to Moussaoui, an unnamed Saudi prince supported him, and the 19 hijackers who flew planes into buildings on September 11, 2001, while they were training to fly

'Nothing to do with me': A 2006 video message, above, purportedly from Osama Bin Laden, featured a voice saying Moussaoui was nothing to do with 9/11

He was in custody on September 11, 2001, and pleaded guilty in April 2005 to conspiring with the hijackers to kill Americans.

During his three-year legal fight, Moussaoui repeatedly insulted the judge and tried to fire his lawyers.

At one point he was facing the death penalty, which jurors decided against. During the hearing he spontaneously declared that he had planned to pilot a plane into the White House on September 11.

A psychologist called by his lawyers testified that Moussaoui had paranoid schizophrenia. Moussaoui mocked the testimony, shouting as he left courtroom, 'Crazy or not crazy? That is the question.'

In 2006 a recording emerged online of Osama bin Laden distancing himself from Moussaoui. He said: 'He had no connection at all with September 11. I am the one in charge of the 19 brothers, and I never assigned brother Zacarias to be with them in that mission.'

Response: The Saudi Arabian government said it had nothing whatsoever to do with the September 11 attacks

Last month, lawyers in a federal lawsuit against Saudi Arabia were permitted to interview Moussaoui in prison.

What was said can't be shared publicly until the U.S. government finishes sifting through the transcript to ensure it contains no secret messages that could pose a threat to Americans.

Jerry S. Goldman, a lawyer who interviewed him, said: 'I will say that we believe it was relevant and material to our case.'

Moussaoui also wrote to the clerk in federal court in Brooklyn in September, saying he had seen a report on Fox News about another suit accusing the Jordan-based Arab Bank of helping finance suicide bombings in Israel. He said he was willing to testify, but the plaintiffs never took it seriously.

The communication wasn't relevant to the Arab Bank case and 'don't make clear what his motives are,' said one lawyer, Gary Osen. 'I don't know his state of mind at all.'