From Krauch, Major Tilley learned quite a bit more about Ambros. That he had been in charge of technical development of chemical weapons production at Gendorf and at Dyhernfurth. That Gendorf produced mustard gas on an industrial scale, and that Dyhernfurth produced tabun. Krauch also revealed a new piece of evidence. Dyhernfurth produced a second nerve agent, one that was even more potent than tabun, called sarin. Sarin was an acronym pieced together from the names of four key persons involved in its development: Schrader and Ambros from IG Farben and, from the German army, two officers named Rüdiger and Linde. Krauch told Major Tilley that the Dyhernfurth plant had fallen into Russian hands.
Karl Krauch said something else that caught Major Tilley by surprise. Before coming to Dustbin, Krauch said he had been in the hospital, where he’d been paid a visit by two American officers, one of whom was Lieutenant Colonel Tarr. “Judging from conversations I had a few months ago in the hospital with members of the USSBS [Colonel Snow] and Chemical Warfare [Colonel Tarr],” Krauch explained, “the gentlemen seemed mostly interested in sarin and tabun; they asked me for construction plans and details of fabrication. As far as I understood they intended to erect similar plants in the U.S.A. I told them to apply to Dr. Ambros and his staff at Gendorf.”
Major Tilley was shocked. Lieutenant Colonel Tarr was his CIOS partner, and yet Tarr had neglected to share with him the story about visiting Krauch in the hospital. This was Tilley’s first indication that Tarr was running a separate mission for the U.S. Chemical Warfare Service, one that apparently had a different objective than the CIOS mission. The full, dramatic story was about to unfold.
By June 1945, Otto Ambros had been questioned by soldiers with the Third Army numerous times. For reasons that remain obscure, no one from that division had been informed of the fact that Ambros was wanted for war crimes, or that he had served as Farben’s chief of chemical weapons production throughout Hitler’s rule. To the Third Army he was simply the “plain chemist” in the Bavarian village of Gendorf, the smiling, well-dressed businessman who supplied American soldiers with free bars of soap.
At Dustbin, Major Tilley relayed this critical new information about Dr. Otto Ambros to his FIAT superiors, who in turn sent an urgent message to the Sixth Army Group, also in Gendorf, ordering the immediate arrest of Dr. Ambros. The Sixth Army was to transport Ambros directly to Dustbin so that Major Tilley could interrogate him. A note card was placed in Ambros’s dossier. Disparate bits of information were now coming into sharp focus. “Case #21877. Dr. Otto Ambros. Rumored to have been involved in use of concentration camp personnel for testing effectiveness of new poison gases developed at Gendorf.”
CROWCASS notified SHAEF, insisting that Dr. Ambros be arrested. As the plant manager at Farben’s Buna factory at Auschwitz, Otto Ambros had been linked to atrocities including mass murder and slavery. The Sixth Army Group swung into action. But when they arrived at Ambros’s home in Gendorf, arrest orders in hand, Ambros was gone.
The first assumption was that Ambros had fled on his own. This proved incorrect. He had been taken away by Lieutenant Colonel Philip Tarr. Initially, the commanding officer at Dustbin found this impossible to comprehend. It was one thing for Tarr to try to interview Ambros before any other chemical warfare experts did. That kind of rivalry had been going on ever since the various scientific intelligence teams had crossed the Rhine. But why would Tarr defy orders from SHAEF to have Ambros arrested? While soldiers with the Sixth Army stood scratching their heads in Gendorf, Tarr and Ambros were actually headed to Heidelberg in a U.S. Army jeep. Their destination was an American interrogation center that was run by army intelligence officers with the Chemical Warfare Service. For days, no one at Dustbin had any idea where Tarr and Ambros had gone.