Attorney General John Ashcroft announced a major blow in the war on terror in March 2003: The government had charged a Muslim cleric with personally handing $20 million to Usama bin Laden.

But as the trial approaches for Sheik Mohammed Ali Hasan al-Moayad (search), the jurors are unlikely to hear that spectacular allegation. Its sole source, an FBI informant from Yemen, set himself on fire in front of the White House late last year, and it is all but certain prosecutors will not put him on the stand.

"The government has acted outrageously and unethically by trumpeting charges that it was not prepared to prove," said al-Moayad's attorney, William Goodman. "Now they're hanging by their fingernails."

U.S. Attorney Roslynn Mauskopf declined to comment.

Al-Moayad, 56, and his Yemeni assistant Mohammed Mohsen Yahya Zayed (search) are charged in federal court in Brooklyn with supporting Al Qaeda (search) and the Palestinian extremist group Hamas (search). Opening statements could start as early as next week, when the two men will join the small number of defendants tried in U.S. courts on Al Qaeda-related charges since the Sept. 11 attacks.

They were arrested in January 2003 after meeting two men they believed to be Muslim radicals at a hotel in Frankfurt, Germany. The radicals were actually FBI informants. Before German police burst into the room, Al-Moayad and the informants discussed funneling $2.5 million into the fight against America's "Zionist government."

Prosecutors' star witness was supposed to be one of those informants, Mohammed Alanssi. But he attempted suicide outside the White House in November, telling The Washington Post that the FBI had broken a promise to make him a millionaire and a U.S. citizen for helping snare al-Moayad.

Defense lawyers said the case was irreparably tainted by the informant's dubious motives and shaky credibility, and prosecutors started mapping out a strategy for proving al-Moayad's guilt without calling Alanssi as a witness.

The government's claim that al-Moayad aided Hamas still appears intact. But lawyers said that with Alanssi out of the trial, the headline-grabbing allegations involving bin Laden appear in danger.

"It shows the weakness of their case," said Howard Jacobs, another of al-Moayad's attorneys. "Without Alanssi, I don't know if the government can prove anything prior to the incident in Germany."

The government's case depends largely on transcripts of recorded conversations in the hotel room. The transcripts support another of Ashcroft's allegations, that al-Moayad claimed to be bin Laden's spiritual adviser.

What Ashcroft did not say, however, was that al-Moayad said on the tapes that his relationship dated to the years when bin Laden was a U.S. ally, battling Soviet forces in Afghanistan. The relationship ended before bin Laden turned against America, al-Moayad said.

Al-Moayad also was recorded boasting of his ties to Hamas militants, promising to give the group money and even handing over receipts for donations to Palestinian charities al-Moayad said helped battle Israel.

He could get more than 60 years in prison if convicted; his assistant, more than 30 years.