Instead, somewhere between Ambros’s release from the Heraus engineering firm in Hanau and his return to Heidelberg, he was able to communicate to his “network of spies and informants in Gendorf.” From those sources, Ambros learned that soldiers with the U.S. Sixth Army had an order to arrest him. So instead of returning to Tarr’s custody, Ambros drove to a fancy guesthouse that IG Farben maintained outside Heidelberg called Villa Kohlhof, where a staff of Farben employees tended to his every need.
CIOS and FIAT officials from Dustbin finally made contact with Tarr and ordered him to return with Ambros to the interrogation facility immediately. But Tarr was no longer in control of Ambros. Major Tilley went looking for Ambros himself and found Hitler’s chemist residing at Villa Kohlhof. Ambros told Major Tilley that he would agree to continue cooperating with the U.S. Chemical Warfare Service and the various Allied agencies that sought information from him, but only on one condition: that Tilley “secure the release of all chemical warfare personnel already detained at Dustbin.” This was a preposterous request.
Tilley’s superior, Major P. M. Wilson of FIAT’s Enemy Personnel Exploitation Section, attempted to take control of the situation, ordering Ambros brought to Dustbin immediately. This was not a matter of cooperation, Wilson said. There were orders to arrest the man. Lieutenant Colonel Tarr intervened on Ambros’s behalf. He lobbied the British Ministry of Supply (the agency responsible for British chemical warfare issues) for help getting Ambros’s Dustbin colleagues released. To Tarr, extracting Ambros’s esoteric knowledge outweighed the need to hold him accountable for his crimes. But the British also flatly refused to help Tarr. The matter stalled.
Lieutenant Colonel Tarr flew to Paris. That night, a telegram arrived at Dustbin, sent from Paris and purporting to be from the British Ministry of Supply. The telegram ordered the release of all Farben chemical warfare scientists at Dustbin, and was signed by a British Ministry of Supply colonel named J. T. M. Childs. Officers at Dustbin suspected that something was amiss and contacted Colonel Childs about his outrageous request. Colonel Childs swore he had neither written the memo nor signed it and accused Lieutenant Colonel Tarr of forgery.
FIAT enhanced their efforts to have Dr. Ambros arrested in Heidelberg. The efforts failed. Ambros was able to evade capture by fleeing into the safety of the French zone. Double-crossing Lieutenant Colonel Tarr, Otto Ambros struck a deal with French chemical weapons experts. In exchange for information, he was given a job as plant manager at Farben’s chemical factory in Ludwigshafen.
When FIAT officers at Dustbin learned what had happened, they were outraged. Ambros’s escape had been entirely preventable. “It is evident that he was not kept in custody or under house arrest,” noted Captain R. E. F. Edelsten, a British officer with the Ministry of Supply. Major P. M. Wilson saw the situation in much darker terms. Lieutenant Colonel Tarr had “taken steps to assist [Ambros] to evade arrest,” he wrote in a scathing report. Wilson was appalled by “the friendly treatment being given to this man who is suspected of war criminality.” But these were just words. Ambros was now a free man, living and working in the French zone.
The relationship among Tarr, Ambros, and the U.S. Chemical Warfare Service was far from over. It was only a matter of time before an American chemical company would learn of the army’s interest in a whole new field of chemical weapons. An American chemist, Dr. Wilhelm Hirschkind, was in Germany at this same time. Dr. Hirschkind was conducting a survey of the German chemical industry for the U.S. Chemical Warfare Service while on temporary leave from the Dow Chemical Company. Dr. Hirschkind had spent several months inspecting IG Farben plants in the U.S. and British zones and now he was in Heidelberg, hoping to meet Ambros. Lieutenant Colonel Tarr reached out to Colonel Weiss, the French commander in charge of IG Farben’s chemical plant in Ludwigshafen, and a meeting was arranged.
On July 28, 1945, Dr. Hirschkind met with Dr. Ambros and Lieutenant Colonel Tarr in Heidelberg. Ambros brought his wartime deputy with him to the meeting, the Farben chemist Jürgen von Klenck. It was von Klenck who, in the final months of the war, had helped Ambros destroy evidence, hide documents, and disguise the Farben factory in Gendorf so that it appeared to produce soap, not chemical weapons. Jürgen von Klenck was initially detained at Dustbin but later released. The Heidelberg meetings lasted several days. When Dr. Wilhelm Hirschkind left, he had these words for Ambros: “I would look forward after the conclusion of the peace treaty [to] continuing our relations [in my position] as a representative of Dow.”