An American student who says he was tortured in Saudi Arabia before arriving in the United States to face terrorism charges told his parents from a Saudi jail that he felt fine and was in good health, prosecutors said in court papers filed yesterday.

Ahmed Omar Abu Ali made the comments in a July 2003 telephone call to his parents in Falls Church, soon after he was detained by the Saudis, prosecutors said. They quoted Abu Ali as saying: "I am doing well. . . . Thank God, my health is great." The court papers also quote him as saying: "Not only am I fine, I am happy." The Arabic translator reported that Abu Ali at times "sounded very cheerful," the court filing said.

Prosecutors said Abu Ali's statements undermine his claims of torture, which have become central to the highly publicized case. Abu Ali, 24, is charged in an al Qaeda plot to kill President Bush and conduct a Sept. 11-style terrorist attack in the United States.

"The defendant's statements . . . are completely inconsistent with those of an individual who purportedly has been tortured and, presumably, would be desperate to return home to his family," Assistant U.S. Attorney David Laufman wrote in the filing in U.S. District Court in Alexandria. He asked a judge to order Abu Ali's attorneys to turn over recordings his parents made of other conversations they had with their son while he was in Saudi custody.

Ashraf Nubani, an attorney for Abu Ali, declined to comment. Prosecutors acknowledged in their filing that Abu Ali could also have been trying to ease the concerns of his parents, who were worried because he was being held in a foreign country.

Abu Ali was arrested by Saudi security officials in June 2003 while he was studying at a university in the country. He was held until he was charged in the United States in February. His conditions of confinement in Saudi Arabia, and whether he was tortured, are expected to play a key role as the case moves toward trial in October.

If a federal judge agrees that Abu Ali was tortured, much of the evidence against him could be thrown out because it was obtained under duress.

As part of their effort to discredit the torture allegations, prosecutors are seeking recordings of other conversations between Abu Ali and his parents. Abu Ali's parents have declined to turn them over, prosecutors said, even though FBI agents served them with a subpoena last week.

"We expect that the other telephone calls recorded by the defendant's parents contain similar evidence that undermines the defendant's torture claims," the filing said.

The Saudis also made recordings of Abu Ali's calls but as yet have been unable to locate any from his first year of confinement, other than the July 31, 2003, call cited by prosecutors. It was the first time Abu Ali called home after he was detained. Prosecutors have obtained recordings of calls Abu Ali made to his parents starting in July 2004.