(WASHINGTON) — President Donald Trump on Tuesday provided no evidence for a conspiracy theory he promoted the day before about a supposed plane full of black-clad protesters he claimed had aimed to disrupt the Republican convention last week.

Trump said in a Monday interview with Fox News that “people that are in the dark shadows” have “control” over his Democratic opponent for the presidency, former Vice President Joe Biden.

“What does that mean?” the right-wing host, Trump ally Laura Ingraham, asked. “That sounds like a conspiracy theory.”

Trump went on: “We had somebody get on a plane from a certain city this weekend, and in the plane it was almost completely loaded with thugs wearing these dark uniforms, black uniforms with gear and this and that. They’re on a plane.”

He said he would say “sometime” where exactly the incident took place and that “it’s under investigation right now.”

“They came from a certain city, and this person was coming to the Republican National Convention, and there were like seven people on the plane like this person, and then a lot of people were on the plane to do big damage,” he said.

Asked by Ingraham if they were “planning for Washington,” Trump replied, “Yes, this was all — this is all happening.”

But when asked about the story by reporters on Tuesday morning, the president said his story was based on “a firsthand account of a plane going from Washington to wherever” — changing the direction the plane was flying, compared to what he claimed the day before. He said he would see whether “the person” who told him the information would speak to reporters.

“That person was on a plane, said that there were about six people like that person, more or less, and what happened is the entire plane filled up with the looters, the anarchists, the rioters — people that obviously were looking for trouble,” Trump said before departing on Air Force One en route to Kenosha, Wisconsin.

It was the latest in a long list of conspiracy theories Trump has promoted, from claiming former President Barack Obama was not born in the United States to recently accepting the support of those who believe in the “QAnon” theory that a global cabal of pedophiles are fighting against Trump.

The White House on Tuesday would not provide any specific information about the president’s story.

White House deputy press secretary Sarah Matthews said in a written statement that the president was “referring to questions that need answers such as who may be funding travel and lodging for organized rioters.”

“An investigation is underway to determine who is funding these organized riots happening across the country,” Matthews said.

The White House pointed to an interview acting Homeland Security Secretary Chad Wolf gave last night to Fox News’ Tucker Carlson, another right-wing television host, in which Wolf said “the Department of Justice is… targeting and investigating the head of these organizations, the individuals that are paying for these individuals to move across the country.”

“What we know, Tucker, is that we have seen groups and individuals move from Portland to other parts of the country,” Wolf added, pointing to the arrests in Kenosha, Wisconsin, of people from out of state.

“We know they’re moving around,” Wolf said. “We’ve seen them in D.C., in Sacramento, and elsewhere. They’re organized. We’ve seen similar tactics being used from Portland and other cities across the country as well. So, we know that there’s organization, I know that the Department of Justice is also looking at that as well.”

Wolf was responding to a question from Carlson in which the Fox host asked why leaders of “antifa” and Black Lives Matter movements have not been arrested.

A Justice Department spokesperson, Kerri Kupec, said Tuesday that the department continues to investigate “coordinated, criminal activity — not First Amendment activity” related to continued riots and unrest in cities around the U.S. in recent weeks.

Kupec declined to comment on the story Trump told during his interview with Fox’s Ingraham.

ABC News’ Alexander Mallin contributed to this report.

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