WASHINGTON -- In sorting out which parts of the story told by Hamid Reza Zakeri are true, German federal police have their work cut out for them.

The Bundeskriminalamt, known as the BKA, has produced Zakeri as a surprise witness in the German government's troubled case against Abdelghani Mzoudi and declared that Zakeri can link Mzoudi to the Sept. 11 terrorist attacks.

But before a five-judge panel Thursday in a Hamburg courtroom, prosecutors acknowledged that BKA agents still are assessing Zakeri's credibility.

They can start with his name. As Zakeri cheerfully admitted during a telephone interview with the Tribune from a hotel room in Germany, the name is a phony one--bestowed on him, he says, during his years of service as an Iranian intelligence agent.

Other parts of Zakeri's story may prove harder to nail down, but also more consequential. Zakeri says the supreme Iranian leader, Ayatollah Ali Khamenei, and the country's former president, Hashemi Rafsanjani, both were fully informed well before Sept. 11, 2001, that a brutal attack on America was planned.

"They were informed by Al Qaeda," which "needed the Iranian government's help," Zakeri says.

He says he knows this because he was working for a security and intelligence unit operating out of Khamenei's office in early 2001, when Iran was visited by Osama bin Laden's chief deputy.

Then, "four months and five days before 9/11," Zakeri says, one of bin Laden's sons, Saad bin Laden, turned up in the Iranian capital, met with Khamenei and Rafsanjani and gave them the details of the Sept. 11 plot.

His account, he says, can be corroborated by the Iranian security agent who served as Saad bin Laden's bodyguard during the visit, and who now is living quietly in Najaf, Iraq.

Zakeri has much more to say: He remembers seeing Mzoudi at the Iranian intelligence headquarters "four years before 9/11."

If confirmed, Zakeri's testimony will not help the 31-year-old Mzoudi who has denied charges that he knowingly assisted the Sept. 11 hijackers in their preparations for worst terrorist attack against the U.S. Moreover, any proven link between Sept. 11 and Iran would pose a challenge for the Bush administration, which has vowed repeatedly to punish any foreign government--as it did the Taliban in Afghanistan--whose fingerprints are found on the attack...