Libyan Nuclear Devices Missing

Libyan officials have acknowledged buying parts for at least 4,000 advanced centrifuges known as P2s -- machines that, when assembled, would have given Libya the capability to produce enough enriched uranium for several nuclear bombs a year. Now, it appears that Libya received only a fraction of the parts needed to build the machines.

Some of the most sensitive parts never arrived there and were not part of the shipment of nuclear parts intercepted by U.S., British and Italian authorities last October, according to U.S. and European officials close to the investigation. "The Libyans did not have the parts to assemble even a single [P2] centrifuge," said one diplomat familiar with the IAEA's probe. "They received thousands of parts, but lacked many of the ones considered to be the most sensitive."

Among the missing components were rotors, the rapidly spinning tubes that make up the core of the centrifuge, as well as bellows, rotor caps and other parts made from a high-strength metal known as maraging steel, U.S. and European sources confirmed. Libyan officials have told investigators they had expected to receive all the parts and in some cases had visited facilities where the components were said to be made.

In the case of the missing rotors, investigators see three possibilities: They were being manufactured by unknown suppliers who have not yet come to light, they were never made or they were shipped and then diverted to another country. Libya did acquire machine tools and high-strength metals that could be used to make rotors, although such an undertaking would have required years to complete and substantial outside help.

One additional shipment of centrifuge parts did turn up in Libya in March, unnoticed by anyone until Libyan authorities discovered the parts and surrendered them to U.S. officials.

In other instances, investigators have obtained documents or intelligence pointing to the existence of parts that were intended for Libya and cannot be traced. Officials familiar with the evidence declined to elaborate, saying they feared the investigation might be compromised.

"The numbers are probably small," said a U.S. intelligence official involved in the probe. "But it's hard to assess the seriousness because we don't know what we don't know."

Adding to the mystery, investigators have discovered discrepancies between the number of centrifuge parts requested by Libya and the quantities the Khan network made. In some cases the production exceeded the demand by a considerable margin, fueling concerns that the smuggling ring had other customers that have not come to light.

"The numbers don't match up," said the diplomat familiar with the IAEA probe, "and we're not yet sure what it means."