Lawyers for families of Sept. 11, 2001, victims say they have documents linking members of Saudi Arabia's royal family to al-Qaida and other extremists.

That evidence, however, may not see the legal light of day because of legal and diplomatic roadblocks in the long-running effort by the families to sue the Saudi government and its leaders in the attacks on New York and Washington, The New York Times reported Wednesday.

The new documents -- including interviews with intermediaries and reviews of money trails -- provided to the Times are among the hundreds of thousand of pages of investigative material the families and insurers have unearthed as part of a civil lawsuit seeking to hold Saudi Arabia and its royal family liable for financing al-Qaida.

Saudi lawyers countered that the ties are weak, saying Saudi Arabia is being sued because of its vast wealth and because it was home to 15 of the 19 hijackers.

"In looking at all the evidence the families brought together, I have not seen one iota of evidence that Saudi Arabia had anything to do with the Sept. 11 (2001) attacks," Michael Kellogg, a Washington lawyer representing Prince Muhammad al-Faisal al-Saud in the lawsuit, told the Times.

Two federal judges and the 2nd U.S. Circuit Court of Appeals ruled against the 7,630 plaintiffs -- survivors and family members of those killed in the attacks -- by throwing out the suit on the ground the families cannot bring legal action in the United States against a sovereign nation and its leaders.

The Supreme Court is expected to decide this week whether to hear an appeal.