FBI wanted Tesla’s ‘death ray’ invention for War Dept, documents show

Nikola Tesla. © Wikipedia
The FBI has finally published its cache of files relating to Nikola Tesla, 73 years after “two truckloads” of his property were seized by the US government following the renowned inventor’s death.

The declassified documents have been released under the Freedom of Information Act and revealed the FBI and government’s serious interest in the death ray - a particle beam weapon which Tesla claimed to have invented.

The long-awaited release also contains information on Tesla’s ball lightning experiments and an FBI plot to arrest a family member who they believed was trying to get his hands on Tesla’s treasure trove of documents.

Serbian-born Tesla is most famous for designing the AC electricity supply system. He was also known for his foresight, predicting the smartphone and video calling.

Tesla died at the age of 85 in a New York hotel suite on what was believed to be January 7, 1943. However, one of the newly-released documents, a letter dated January 12, 1943 states that an inquiry established Tesla actually died on January 8.

It also detailed how the government office of Alien Property Control seized all of Tesla’s property, sealed all articles and brought them to the Manhattan storage warehouse in New York City.


The letter expressed concern that, as Tesla was a naturalized US citizen, they may not have jurisdiction over his property but felt confident they could keep the material from any other agency for at least two days.

In 1951 an American court declared that Sava Kosanovic, was the rightful heir to the property and the material was transferred to Belgrade and is now housed in the Nikola Tesla Museum in Belgrade.

Also among the documents released is a letter addressed to J Edgar Hoover, the first Director of the FBI, highlighting an article about Tesla’s death ray invention, suggesting it could be of “vital importance” to the War Department, “as well as that of other nations now controlled by insane dictators”.


It also recommended the “constant guarding” of Tesla to ensure his protection against “alien enemies” who may be interested in “the secret of such an invaluable instrument of war and/or defense”.

Another document shows the FBI’s concern that a nephew, Sava Kosanovic, whom they said Tesla “intensely disliked” was trying to gain possession of “these important documents and plans”. The Bureau also feared that he would “make such information available to the enemy”.


A memorandum in the FBI records dated January 9, 1943, stated that Tesla had performed many experiments in connection with the wireless transmission of electrical power, “commonly called the death ray”.

A protege of Tesla, Bloyce Fitzgerald, said in an interview with a government official that Tesla told him just a month before his death that these experiments had been completed and perfected. Fitzgerald said he was also aware of a revolutionary type of torpedo designed by Tesla.


Previously the public were told that rumors of death ray technology were nothing more than that.

The FBI said it was not involved in searching Tesla’s effects, and it never had possession of his papers or any microfilm that may have been made of those papers.