An American Muslim convicted of plotting to assassinate President Bush had been tortured into confessing and was denied his constitutional right to confront his accusers, his attorney told a federal appeals court Thursday.

Ahmed Omar Abu Ali claims Saudi security officials whipped and tortured him into giving a false confession, attorney Joshua Draytel said.

Draytel also claimed his client's constitutional right to confront his accusers "took a ferocious beating" because the Saudis testified from Riyadh while Abu Ali was in a Virginia courtroom.

Abu Ali should have been taken to Saudi Arabia since the Saudi government would not allow its agents to come to the U.S., Draytel said.

Assistant U.S. Attorney David H. Laufman countered that Abu Ali's trial in November 2005 was fair and that there was no doubt about the validity of his written and videotaped confessions.

"The sheer detail of these confessions is astonishing," Laufman told the three-judge panel of the 4th U.S. Circuit Court of Appeals, which later conducted a closed session focusing on classified information.

The court will likely issue its ruling in several weeks.

Abu Ali, a U.S. citizen born to a Jordanian father and raised in Falls Church, Va., is serving 30 years for conspiracy to assassinate the president, conspiracy to hijack aircraft and providing support to Al Qaeda.

Prosecutors said Abu Ali traveled to Saudi Arabia and joined Al Qaeda out of hatred for the United States. The Saudis arrested Abu Ali in June 2003 as he was taking final exams at the Islamic University of Medina.

Abu Ali gave the Saudis a statement saying he joined Al Qaeda and discussed with some senior members Bush's assassination and other terror plots. The jury in Abu Ali's trial saw his videotaped confession.

Laufman said security concerns precluded taking Abu Ali to Saudi Arabia. He also said the Sixth Amendment "does not guarantee a defendant a face-to-face encounter" with his accuser.

Judge J. Harvie Wilkinson III pressed Draytel on the torture issue, asking how he could argue such coercion when the videotape "showed the defendant rocking back and forth and smiling."

Draytel referred the court to his written briefs, saying he wanted to spend his limited time on the Sixth Amendment issue and his claim that there was insufficient evidence to corroborate the confession.

Wilkinson said only "bare bones" confessions are typically suppressed because of a lack of corroborating evidence.

"These are among the most detailed confessions I've seen," the judge said.

On cross-appeal, the government is challenging Abu Ali's 30-year sentence as too lenient.

He faced a maximum of life in prison, but U.S. District Judge Gerald Bruce Lee said 30 years was sufficient considering the 20-year term given to John Walker Lindh, who was captured on the battlefield in Afghanistan in November 2001 during the U.S.-led effort to topple the Taliban.