Journalist and biographer Timothy O'Brien once caught President Donald Trump in yet another lie about the artwork on his walls, Vanity Fair reported Friday.

While O'Brien was researching his biography, TrumpNation: The Art of Being the Donald, he joined Trump on his private jet en route to Los Angeles. Hanging on the wall was the Renoir painting "Two Sisters on the Terrace." O'Brien asked Trump if it was a real Renoir painting, but he already knew the answer. Trump swore that it was.

“No, it’s not Donald,” O’Brien replied, calling him out. Trump swore that it was. O'Brien explained that he was from Chicago and that the painting was hanging on the wall at the Art Institute of Chicago. "That's not an original."

Trump maintained that it was and O'Brien dropped it, moving on to his interview. But Trump wasn't over it. Later, while they were flying back to New York from Los Angeles, Trump pointed to the painting and proudly said, "You know, that's an original Renoir," as if he'd forgotten the preliminary conversation ever took place. O'Brien didn't engage.

The most damaging piece of O'Brien's book ended up being that Trump wasn't a multi-billionaire as he has claimed. Rather, Trump's alleged worth was approximately $150 to $250 million. Trump sued O'Brien for "malice" and loss.

In 2016, when Trump was elected, he sat down with "60 Minutes" for the first interviews, which took place in Trump Tower. In the background hung the fake Renoir.

“I’m sure he’s still telling people who come into the apartment, ‘It’s an original, it’s an original,’” O’Brien told the "Inside the Hive" podcast this week.

“He believes his own lies in a way that lasts for decades,” O’Brien explained. “He’ll tell the same stories time and time again, regardless of whether or not facts are right in front of his face.” He went on to say that's what makes Trump so dangerous when it comes specifically to his war with the media and claims of "fake news."

“It’s foundation is that he’s the final arbiter of what is true and what isn’t,” O’Brien said, “and it’s one of the reasons that he’s so dangerous.”

Trump got caught earlier this year with a fake TIME magazine cover hanging on the wall of his hotel properties. TIME demanded that they be removed.

As a Twitter user pointed out, Melania Trump has another fake Renoir in her office, Renoir at the Theatre: Looking at La Loge. That painting is on display at The Courtauld Institute of Art in London, though there is no record of the Trump's claiming it was. The only indication came from captions placed on the Sam Horine photos by the Daily Mail.

Below you can see the clip of the "60 Minutes" interview in which the fake painting appears in the background: