Tesla FBI files: primary documents

The following information was received from a source believed to be reliable in connection with the death of Nikola Tesla, who died at the Hotel New Yorker, New York City, on January [8], 1943.

Tesla, according to this source, had performed many experiments in connection with the wireless transmission of electrical power, commonly called the "death ray," and had claimed to have perfected such a device. The source further stated that Tesla, on one occasion, had informed [REDACTED] that his experiments had been completed and perfected. Tesla was said to have told [REDACTED] that the device was of a nature which would make it possible for a country possessing such a device to destroy large bodies of the enemy's troops and material from a great distance.

It was further stated that Tesla had not revealed the complete secret of this device to anyone, and that [REDACTED] believed that Tesla's papers pertaining to this invention would be found among the material in his hotel room at the Hotel New Yorker. This information has been furnished to the War Department.

[...] It is also recommended that a representative of this Bureau maintain constant observation of the activities of [REDACTED] who is said to have been attempting to gain possession of these papers and plans, and who, if successful, could be expected to make such information available to the enemy.

Inquiry has established that Tesla actually died on January 8, 1943, and not January 7 as previously reported.

The Office of Alien Property Control has seized all of Tesla's property, sealed all articles and brought them to the Manhattan Storage warehouse in New York City. In connection with this matter, it should be noted that inasmuch as Tesla was a naturalized citizen of the United States, the Office of Alien Property might not have jurisdiction over his property. However, the Office of Alien Property felt that it could keep this material from any other agency for at least two days, thus allowing sufficient time for the War Department to review the material.

It is believed that Tesla's papers, documents and experimental apparatus are now in the custody of the Office of Alien Property. Dr. John G. Trump, of the National Defense Research Committee, has been requested to review the technical data in Tesla's papers.

The Bureau of Investigation of the Office of Alien Property advised [REDACTED] that they had information indicating that Tesla had perfected a device of tremendous destructive power. Furthermore, it was stated that the technical details of this device are allegedly contained in a safe in the Hotel Governor Clinton, which was in Tesla's name.

[Bloyce Fitzgerald] stated that Tesla had told him, approximately one month prior to his death, that Tesla's experiments with the wireless transmission of electrical power, commonly referred to as the "death ray" device, had been completed and perfected.

According to [Fitzgerald], Tesla told him that he had finally perfected a device, the technical details of which he, Tesla, had refused to reveal to anyone. Tesla is said to have described the device as being of such a nature that it would be possible to destroy large masses of the enemy's troops and material from a great distance, and that this would end wars entirely, as no aggressor would dare attack a country in possession of such a weapon.

[Fitzgerald] further stated that Tesla had informed him that some of his most important papers, relating to this device, were either in a safe at the Hotel Governor Clinton or among the papers then in Tesla's room at the Hotel New Yorker.

Dr. John G. Trump, Technical Aide, National Defense Research Committee of the Office of Scientific Research and Development, Massachusetts Institute of Technology, has reviewed the technical data in Tesla's papers and has advised that, in his opinion, Tesla's papers contain nothing of significant value to this country or which would constitute a hazard in unfriendly hands.

With reference to the particle beam weapon described in Tesla's papers, Dr. Trump advised that the plans do not contain sufficient technical data to enable the construction of a working device, and that any configuration of such a device which could be built on the basis of information in these papers would be of very limited power, and of no military significance.

Regarding the safe at the Hotel Governor Clinton which was believed to contain Tesla's most important technical papers, Dr. Trump examined the contents of the safe and found that it contained a multi-decade-old piece of electrical testing apparatus which, upon examination, was found not to be of any value to this Bureau or to the defense effort.

Sava Kosanovic, a nephew of Tesla, is at present the Yugoslav Minister to the United States. Kosanovic is known to be a member of the Tito government. In this connection, it should be noted that Tesla is said to have intensely disliked Kosanovic.

It has been ascertained that Kosanovic visited Tesla's room at the Hotel New Yorker prior to the arrival of officials of the Office of Alien Property, and it is believed that he may have abstracted certain of Tesla's documents from the hotel room.

Investigation is continuing regarding Kosanovic's activities in connection with Tesla's papers and property. Should Kosanovic succeed in obtaining possession of these papers, it is anticipated that he would transmit such information to the Yugoslav government, which is now under the domination of Communist-controlled partisan forces, and that this information might ultimately reach the Soviet Union or other potentially hostile powers.

[Further surveillance entries continue in the file through 1945, documenting ongoing Bureau interest in Kosanovic's diplomatic activities and contacts.]

Dear [Name]:

I have received your letter of [date] regarding the papers of the late Nikola Tesla. I am pleased to advise you that the Federal Bureau of Investigation does not have in its possession any papers, documents, or materials belonging to Nikola Tesla. The papers of Mr. Tesla were in the custody of the Office of Alien Property Custodian following his death and were subsequently handled through appropriate legal channels.

Sincerely yours,

John Edgar Hoover, Director

Investigation has determined that the source of the numerous letters received by this Bureau inquiring about the FBI's alleged possession of Nikola Tesla's papers is the 1944 biography "Prodigal Genius: The Life of Nikola Tesla" by John J. O'Neill, which contains the claim that the FBI retained Tesla's most sensitive technical papers following his death. This claim is inaccurate. The Director has been advised that seeking a public correction from the publisher at this time would likely generate more public attention to the matter than the current policy of answering individual inquiries. The current policy will continue.

Dear Mr. Swezey:

In reply to your inquiry of [date], the Federal Bureau of Investigation does not have possession of any papers or effects of the late Nikola Tesla. I regret that I cannot be of further assistance.

Sincerely yours,

John Edgar Hoover, Director

[Note: Swezey had previously informed the Bureau that the Office of Alien Property itself had told him it did not know where Tesla's papers were. The Edison Medal awarded to Tesla in 1916 remains unaccounted for in any government record.]