He once led a team, he told BND officers, that equipped trucks to brew deadly bio-agents. He named six sites where Iraq might be hiding biological warfare vehicles. Three already were operating. A farm program to boost crop yields was cover for Iraq's new biological weapons production program, he said.

Germany provided Europe's most generous benefits to Iraqi refugees, and several hundred arrived each month. But few had useful credible intelligence on Baghdad's suspected weapons programs. Intelligence agents became accustomed to exaggerated claims.

"The Iraqis were adept at feeding us what we wanted to hear," said a former official of the Pentagon's Defense Intelligence Agency who helped debrief about 50 Iraqi emigres in Germany before the war. "Most of it was garbage.''

But for this defector, the Germans assigned two case officers as well as a team of chemists, biologists and other experts. They debriefed him from January 2000 to September 2001.

Since the Iraqi had arrived in Munich, U.S. liaison with German intelligence was assigned to the local DIA team. Their clandestine operating base was an elegant 19th century mansion known as Munich House. There he was assigned his codename: Curveball.