President Donald Trump has continued to question the legitimacy of former President Barack Obama’s birth certificate during private conversations in recent months, The New York Times reported, citing advisers who discussed Trump’s statements.

Trump still questioning Obama’s birthplace is just one of several instances The Times pointed to as examples of the President’s reliance on “manufactured facts,” as the newspaper reported Tuesday.

One sitting US senator quoted by the Times, “who listened as the President revived his doubts” about the issue, “chuckled” when speaking about what was said. Trump “has had a hard time letting go of his claim that Mr. Obama was not born in the United States,” the senator, who “asked not to be named to discuss private conversations,” told The New York Times.

CNN has not independently confirmed the reporting. The White House did not immediately return CNN’s request for comment.

Although Obama was born in Hawaii in 1961, Trump publicly questioned Obama’s citizenship for several years before saying in a news conference during the 2016 election that he believed the nation’s first African-American president was born in the US.

In September 2016, Trump said, “President Barack Obama was born in the United States.”

The White House released copies of Obama’s original long-form birth certificate in 2011 in an attempt to put the rumors to bed.

Tuesday’s report comes days after The Times reported that Trump also was questioning the authenticity of the infamous “Access Hollywood” tape.

The tape was a recording from several years ago in which Trump could be heard bragging about groping women, and Trump apologized soon after the tape surfaced last fall.