It looked like a successful strike against Al Qaeda in Europe. Last month German police raided a suspected terrorist cell in Berlin, arresting a half-dozen men and seizing bomb-making equipment, flight-simulator software and chemicals. Now the investigation has taken an unexpected turn. German officials say the terror suspects may have had a highly placed friend: a top diplomat at the Saudi Embassy in Berlin. Sources say Muhammad J. Fakihi, chief of the embassy's Islamic-affairs branch, met frequently with the suspected terrorist cell's leader, Ihsan Garnaoui, at Berlin's Al Nur mosque--a notorious haven for Islamic extremists. The Germans confronted the Saudis and threatened to declare Fakihi persona non grata. "We don't do that unless the evidence is very grave," says a German official. Four days after the arrests, Fakihi left Germany and was supposed to have returned to Saudi Arabia. But, NEWSWEEK has learned, he never showed up. Now the Saudis want him for questioning, and officials are uncertain of his whereabouts. "There is close cooperation between the Saudi and German authorities on this matter, and we intend to get to the bottom of it," says one Saudi official. U.S. officials were already aware of Fakihi: his business card had been found in the apartment of Mounir el-Motassadeq, who was convicted of being an accomplice of the "Hamburg cell" that committed the 9-11 attacks.