Here is the Jewish Telegraphic Agency report from Nov 25, 1942
https://www.jta.org/1942/11/25/archive/hitler-has-ordered-annihilation-of-all-jews-by-end-of-1942-washington-hears
Dr. Stephen S. Wise, president of the American Jewish Congress, after a conference today with Under-Secretary of State Sumner Welles and other high officials of the State Department, declared that Hitler has ordered the annihilation of all Jews in Europe by the end of this year.
“This news is substantiated in documents furnished to me by the State Department this afternoon,” Dr. Wise said. “It is one of the last made acts of destruction which Hitler will perpetrate before he is called to judgement.”
Note that Wise strongly implies that the "information" had been substantiated by the State Department. But in fact all he says is that the State Department passed along some documents to him.
Declaring that a representative of President Roosevelt, who returned a short time ago from a mission abroad, told him that “the worst fears about the fate of the Jews under Hitler are true,” Dr. Wise estimated that “one-half of the five million Jews in the territories occupied by the Nazis have already been destroyed.”
Dr. Wise said that he has been receiving reports for three months indicating that Hitler has been extremely wrathful because the extermination of the Jews has not proceeded more quickly. “The Nazis,” he declared, “have used various means of killing off large portions of the Jewish population, including poison and asphyxiation, but have now found that the most efficient method is for a doctor to inject an air bubble into the victims’ veins. In this way a single doctor can kill 100 persons in an hour.” He added that the Nazis have set a value of fifty marks, about ten dollars at pre-war rate of exchange, for each corpse, and are reclaiming them for soap fats and fertilizer. Corpses are also being exhumed for this purpose, he said.
And then from the NYT from Nov 26, "Slain Polish Jews Put at a Million," we have an account of the same press conference.
Rabbi Wise explained that his group believed in the authenticity of the extirpation order on the strength of affidavits obtained by the State Department from Jewish sources of information in free countries.
[...]
Rabbi Wise said the State Department documents included affidavits from "reliable persons who knew" of such atrocities as turning Jewish bodies into fats and soap and lubricants, and of the latest Nazi method of killing Jews by having doctors inject air bubbles into their veins. He said that earlier gassing with prussic acid had been found too expensive.
Even by Holocaust standards, these claims are pretty wild. From the NYT account, we learn that the ultimate source for the "information" was a collection of "affidavits" from Jewish sources which the State Department had merely passed on. In the months previous, the State Department had elected not to forward some of this kind of stuff to Wise and the Jews had raised a fuss about it. (Tangentially, it's interesting that Wise says here that the Germans had abandoned Prussic acid in late 1942 due to cost).
Not surprisingly, this announcement was meant with some skepticism in the press, particularly the assertion that the State Department vouched for the claims. The editors of The Christian Century, an American Protestant publication, openly challenged Wise with a December 9th editorial, "Horror Stories from Poland." The editors noted that “although Rabbi Wise went out of his way to place the responsibility for his charges on the State Department, that branch of the government has conspicuously refrained from issuing any confirmation.” They further remarked that Wise's soap story was ”unpleasantly reminiscent of the ‘cadaver factor’ lie which was one of the propaganda triumphs of the First World War.”
Wise responded indignantly with a letter published on Jan 13, 1943. “It would appear that you are more interested in seeking to prove that figures which I gave out in the name of five important Jewish organizations of America are inaccurate in respect to Jewish mass massacres in Hitler-occupied countries than you are in making clear to American Christians how unspeakable has been the conduct of Hitlerism against the Jewish people.” He then accused them of having a “frankly or disguisedly anti-Jewish attitude whenever it deals with Jewish subjects"... “Whether this is merely a reflection of a personal Judeophobia on the part of the editor, or whether it conveys the considerable attitude of the editorial board of The Christian Century is not for me to say. Christian ministers with whom I have discussed the problem have felt your article reflected the subconscious desire not so much to express compassion for the victims of Hitlerism as to shield Hitler from the consequences of his crime. I confess that I cannot quite understand that you should seem to be spiritually unconcerned about the tragic fate of the people whose gift to the world you purport to revere and worship. I take it for granted that the above letter will appear in the columns of The Christian Century, and for your sake I trust a deeply penitential word of your own may be added.” He also reiterated his claim about the State Department confirmation.
Wise was not aware that the editors had already contacted the State Department before running the editorial. The editors shot back that they had indeed “taken the trouble to inquire." “The state department promptly replied through an accredited officer. Unfortunately, it specified that its reply was 'not for publication.' We have that reply in our files; it does not support Dr. Wise’s contentions. Our editorial comment on his charges was written in the light of the state department’s reply to our question.”
I was pleased to see that Walter Laqueur identifies the accredited officer as M.J. McDermot, chief of the Division of Current Information, and he supplies McDermot's full response.
I today informed correspondents in confidence and am glad to give to you, not for publication, that Rabbi Wise was in the Department several months ago and again yesterday and he had consulted with the Department in connection with certain material in which he was interested and he now has this material. The State Department had only sought to facilitate the efforts of his Committee in getting at the truth and the correspondents should direct all questions concerning this material to Rabbi Wise.
Laqueur then comments: “In short, the State Department wanted to have nothing to do with the content of the message.”
Sources
Robert Ross, So It Was True, pg 173-175
Deborah Lipstadt, Beyond Belief, pg 183-185
Walter Laqueur, The Terrible Secret, pg 227
Rafael Medoff, The Jews Must Keep Quiet, pg 123-125
Peter Novick, The Holocaust in American Life, pg 287
Ross is a Protestant. His account of this episode is reasonably fair. Lipstadt, Laqueur, and Medoff are Jewish writers and they all spin the skepticism of the editors as something of a scandal. Novick is also a Jew but more in the Norman Finkelstein mold. He only briefly discusses it in an endnote; he is critical of Wise and doesn't try to hide his deception : "A few days earlier, representatives of the American Jewish Committee and of B’nai B’rith had pressed Stephen Wise of the American Jewish Congress as to whether the State Department vouched for the veracity of the “soap” story, and wished it disseminated. Wise assured them--falsely--that this was the case." Of all the accounts, Medoff's is the most grating because he goes out of his way to cover for Wise and also somehow avoids mentioning the soap claim so the reader never has any idea of how ridiculous Wise's claims actually were. Lipstadt to her credit not only mentions the soap but also the air bubble injection but I think it's because she's so dumb she doesn't realize that you're supposed to bury such embarrassing stories.