Washington (CNN) President Donald Trump maintains that the Pierre-Auguste Renoir "Two Sisters (On The Terrace)" painting in his New York apartment is the original. But according to Trump biographer Tim O'Brien -- and the Art Institute of Chicago -- that may be fake news.

In an interview with Vanity Fair's " Inside the Hive" podcast earlier this week, O'Brien -- a Chicago native -- recounted talking to Trump years ago while on the businessman's private jet.

O'Brien said he spotted the Renoir portrait and asked Trump if it was an original. Trump said it was. O'Brien verbally disagreed, but Trump continued to protest O'Brien's argument. According to Vanity Fair, O'Brien "dropped the conversation topic and moved on with his interview."

"I'm sure he's still telling people who come into the apartment, 'It's an original, it's an original,'" O'Brien told Vanity Fair in the podcast interview.

In 2006, Trump sued O'Brien, author of "TrumpNation: The Art of Being the Donald," for writing in his book that Trump's net worth was $150 million to $250 million. Trump lost the lawsuit.

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