President Donald Trump personally called the head of the National Park Service on the day after his inauguration to ask for photographic evidence that would support his claims about the size of the crowd at the event, The Washington Post reported .

A National Park Service official confirmed to The Huffington Post that the call took place on Saturday but would not comment further.

Trump falsely claimed up to 1.5 million people attended his inauguration, boasting that the crowd extended from the Capitol to the Washington Monument and accusing the media of lying about how many attended. White House Press Secretary Sean Spicer has pushed similar false claims, which Trump adviser Kellyanne Conway defended as alternative facts.

Trump reiterated those boasts in an interview with ABC News that aired Wednesday.

Look how far back it goes, he said, pointing to a photograph of his inauguration. This crowd was massive. And I would actually take that camera and take your time if you want to know the truth.

In reality, photos taken of the National Mall during the ceremony showed wide swaths of open space near the monument, and one crowd estimator has concluded that 300,000 to 600,000 people attended the Jan. 20 ceremony roughly a third of the people who attended President Barack Obama s inauguration in 2009.