The FBI was very concerned about whether Americans recruited by the Haganah in 1947-48 violated the Neutrality Acts, which barred the export of arms to belligerent nations and forbade U.S. citizens from traveling on belligerent ships. At the end of 1947, for example, ten merchant seaman who served on the S.S. Tradewinds and S.S. Exodus drew attention when they sought passports to return to the United States. The FBI was concerned that some had been contacted by Soviet agents. Apparently special agents investigated each for espionage and filed reports but their findings are not found in the documents.
The FBI also investigated the Haganah’s American support group, Americans for Haganah, Inc., to see if it violated the Voorhis Act, which was adopted in 1939, and required registration of certain organizations that advocated the overthrow of the United States government. The document notes the Haganah denied its activities came within the purview of the Act. The FBI director gave instructions to investigate the veracity of the claim discreetly to “assure no undue criticism will be directed against the Bureau because of this inquiry.
In April 1948, the FBI was also interested in the activities of someone [the name was redacted] who may have been the head of intelligence for the Haganah. Another memo in July 1948 gave instructions to “develop all information indicating possible violations of the Neutrality Act and the Registration Act” and to identify individuals and organizations involved. It appears the investigation was closed by the end of November, though the FBI continued to monitor Haganah activities.