(CNN)President Donald Trump has come under fire for using the name of a famous Native American as a slur -- at an event honoring Native Americans for their service as code talkers in World War II, no less.
Trump's family denied German heritage for years
Trump turned to his often-used insult of "Pocahontas" to slam Sen. Elizabeth Warren, whom he claims has embellished her purported Native American heritage. Warren has said she was raised being told that she is part Native American, but has maintained that she never used this aspect of her heritage to advance her career.
Trump's repeated attacks on Warren come despite his own family's past efforts to hide their heritage. According to multiple reports from The New York Times and the Boston Globe and a biography, Trump's father repeatedly sought to conceal the fact that he was the son of German immigrants.
Fred Trump sought to pass himself off as Swedish amid anti-German sentiment sparked by World War II. According to the biography "The Trumps: Three Generations that Built an Empire" by Gwenda Blair, Fred Trump denied knowing German and did not teach it to his children.
John Walter, a Trump family historian and one of Donald Trump's cousins, said this was an effort to not offend his Jewish customers.
"He said, 'You don't sell apartments after the war if you're German,' " Walter said in the Boston Globe article. "So he's Swedish, no problem."
Even after World War II, Fred Trump continued to claim he was Swedish, according to Walter.
Walter declined to comment to CNN on the family's heritage when reached by phone on Tuesday. CNN also has reached out to the White House for comment.
In his book, "The Art of the Deal," Donald Trump reaffirmed the myth of his family's origins, writing that his father's father came to America "from Sweden as a child."
In reality, Fred Trump's father, Friedrich Trump, immigrated to the United States from the German city of Kallstadt as a teenager in 1885. Blair writes in her biography that Friedrich Trump went on to establish several saloons and hotels that doubled as brothels.
One German historian alleges that the Trump patriarch was kicked out of Germany for failing to complete mandatory military service and as such was not able to reclaim his German citizenship.
Donald Trump eventually acknowledged and embraced his German heritage, serving as the grand marshal of the annual German-American Steuben Parade in New York City in 1999. In a video message for the 2011 event, Trump touted his grandfather's immigration story and recalled the earlier parade.
"We passed Trump Tower, 69 stories. I looked up and I said, 'This is a long way from Kallstadt,'" he said, referring to his grandfather's hometown.
"I'm a proud German-American," Donald Trump added.
Despite his public acknowledgment of his German heritage, it is unclear if the President has ever fully corrected the record about his family's past claims of being Swedish.
When asked by the Boston Globe why his father claimed he was Swedish, Donald Trump said, "Well, he spent time in Sweden. And he talked about Swedish because of the fact, you know, we happened to be at war with Germany, which I guess makes sense in a lot of ways doesn't it? But he spent time in Sweden."
When the Globe pressed him as to why he maintained the false story, he said, "Well, it was never really something discussed. My father spent a lot of time there. But it was never really something really discussed very much."