On April 22, 1945, near the end of the war, Kurt Gerstein surrendered to the French, who arrested him as an alleged war criminal. They took him to the Cherche-Midi Military Prison on July 5, 1945. On July 23, 1945, the Swedish diplomat, Baron Göran von Otter, then in Helsinki, wrote to his London colleague, Baron Lagerfelt, strongly urging that something be done to help a German named Gerstein, and asking Lagerfelt to bring the matter to the Allied authorities.
It was too late. Kurt Gerstein was found dead in his cell on July 25, 1945.
In his book A Spy For God: The Ordeal of Kurt Gerstein the author Pierre Joffroy tells about his death and the witnesses:
Leon Entz (1968): “I was on duty on the second floor. We went the rounds at two and checked the prisoners. I knew the one who had been put in solitary. He scarcely said anything although he could have talked to me because I speak German. I went round that day at two as usual. When we went in they stood to attention and clicked their heels.
But when I opened the door of his cell there wasn’t a sound. I went in and saw his body hanging from the ventilation grille.”
Alexader Auer, sergeant in charge (1969): “Entz shouted to me down the corridor to come at once. I went in and saw the mand had hanged himself. I knew him, a tall silent man, very depressed. He had once or twice said in German: ‘ I’ve nothing to reproach myself with, nothing.’”
Dr. Jackues Trouillet (1945):”At 17:25 on that day I signed the death certificate of the prisoner Gerstein. That the death was caused by hanging was clearly evident from the furrow round the neck and the position of the body when found. It is a form of suicide that cannot possibly be prevented in a prison.”
Whether he committed suicide out of despair and guilt in not being able to stop the Holocaust or whether he was murdered by other SS officers in the prison remains a mystery. In his book The Ambiguity of Good Saul Friedlander tells that among Gerstein’s papers was found the opening portion of a letter he had begun to write before he was transferred to France, addressed to his Dutch friend H. J. Ubbink:
“Dear Friend Ubbink
You are one of the first to whom I shall send greetings. Let me congratulate you from the bottom of my heart on the liberation of your country from our brood of vipers and criminals. However dark our fate may now be, those terrible people could not be allowed to win. Ask your people if, now at least, they believe what went on in Blezec, etc. I thank God that I did everything in my power to cut through this abscess on the body of humanity.”
Kurt Gerstein was buried in the Thiais cemetery under the name Gastein. But even that was temporary, for his grave was within a section of the cemetery that was razed in 1956.
In 1950, a denazification court posthumously condemned him: “Taking into account the extenuating circumstances noted the court has not included the accused among the main criminals but has placed him among the ‘tainted’ ..” It was not until January 20, 1965, that Kurt Gerstein was cleared of all charges, by the Premier of Baden-Württemberg.
While in prison Gerstein turned over to a French intelligence team his detailed report on atrocities in Belzec and Treblinka. His date provided the Allies in later trials with their most detailed accounts of the Nazi murder mills, and it was used at the Nuremberg Trials.
Kurt Gerstein’s report became perhaps the most horrifying eyewitness account of the Holocaust. After the war the basic facts of his report were verified by SS Obersturmbannführer Wilhelm Pfannenstiel before the Land-Court of Darmstadt in the Federal Republic of Germany, on June 6, 1950.

During an interrogation in the Court at Tuebingen, on February 16, 1961, Elfriede Gerstein confirmed her husband’s signatures and his handwriting.