In 1937, while in Vienna with his family, he was caught in a pogrom in which his teeth were smashed out, tongue slashed, arms and legs broken, and he was beaten unconscious and left for dead.

The file also purportedly states that Gruenwald asked British authorities to stop a ship carrying refugees, the SS Patria, from entering Palestine.

[6] In the early 1950s, Gruenwald decided to devote his remaining years to journalism, but as Ben Hecht writes, no one was about to employ a 72-year-old man who wrote no Hebrew.

Gruenwald therefore began self-publishing a more-or-less weekly three-page mimeographed pamphlet, which he would have translated from German into Hebrew before distributing up to 1,000 copies himself,[7] by mail or by hand in local cafés, all free of charge.

[7] Occasionally, one of the targets of his pamphlets would threaten to sue him for libel; in response, Gruenwald would make a public apology, often in the "Café Vienna", which occupied the ground floor of his hotel.

[8][9] This one accused Rudolf Kastner — the press spokesman for the Israeli Ministry of Commerce and Industry, a senior member of Mapai, and the former de facto head of the Hungarian-Jewish Aid and Rescue Committee during the Holocaust — of being a Nazi collaborator.

According to Hecht, Gruenwald obtained his information from an anonymous letter and a conversation with a stranger at the "Café Vienna",[10] though a 1955 Time Magazine article says he was attempting to discover who had betrayed his relatives in Hungary, and drew his conclusions "after poring through mountains of yellowed records".

[11] The actual text of the pamphlet included the following: I have waited a long time to expose this careerist whom I consider, because of his collaboration with the Nazis, an indirect murderer of my dear people.

Who is this spokesman for the Ministry of Trade and Industry; who is this big shot leader of the Hungarian Jews; who is this fellow who has been put high on the list of candidates for Israel's parliament by the government party Mapai?

[12] Gruenwald concluded his charges as follows: He wanted to save himself, so that Becher would not reveal to international court their deals and their joint acts of robbery... Where now is the money of the Jews of Hungary, millions for which no accounting is given...

In Cohen's words, "in our new, pure, ideal State ... a man cannot officiate in a senior position ... when there is a stain on him, or even only a grave suspicion of collaboration with the Nazis".