There are no official records or credible media reports to confirm that Fred Trump was a Nazi spy.
Donald Trump's father, Fred Trump, had owned many renting homes in New York in the early 1930s. Some unconfirmed reports suggest that he did not allow Black tenants, including Black veterans of war. In 1927, he was arrested during a Ku Klux Klan rally in Jamaica, Queens. He was arrested along with seven men and was discharged later. The reports do not specify if he participated in the parade or if he was a Klan member. Alberto Martinez, a historian at the University of Texas, wrote in his research article that based on the evidence he had reviewed, Fred might have been just a local, who went to the Memorial Day parade and got involved in the riot that occurred in his neighborhood. Later the police arrested him and released on the same day with no charges.
Even though a report claimed that many Nazi spies lived close to where Fred Trump was, there is no concrete evidence to tie him to the Nazis. The absence of reliable sources and official government documents suggest that Mr. Fred Trump was not related to the Nazis and that he was not a Nazi spy.