Matt Schlapp, chairman of the American Conservative Union, arrives to introduce President Donald Trump during the Conservative Political Action Conference (CPAC) at National Harbor in Oxon Hill, Maryland, February 29, 2020.

The operator of the Maryland hotel which recently hosted a major conservative political convention has denied claims by conservative activist Matt Schlapp that state health officials "did 2,000 screens all around the hotel" for the coronavirus after an attendee tested positive for the disease.

Schlapp said Monday on Twitter and later in a Fox News interview that Maryland health officials had told his American Conservative Union that those screenings were done after they learned a man at the Conservative Political Action Conference had been diagnosed with the coronavirus days after the conference ended Feb. 29.

Several members of Congress announced Monday that they were self-quarantining because they had contact in late February with the man during CPAC at the Gaylord National Resort & Convention Center, which is located in National Harbor, just outside of Washington, D.C.

The annual conference run by ACU is a highlight of conservatives' calendars, and was attended by President Donald Trump and Vice President Mike Pence this year.

"They did 2,000 screens all around the hotel," Schlapp told Fox News host Laura Ingraham via Skype from his home, where he was in self-quarantine because of his exposure to the same CPAC attendee.

"They found nothing," he said.

"Several days ago they came to us and said there's nothing to be alarmed about," said Schlapp, a lobbyist who is the ACU's chairman.

Schlapp's wife, Mercedes Schlapp, now works for President Donald Trump's reelection campaign, and previously served as director of strategic communications in the Trump White House.

Allison Sitch, a spokeswoman for Marriott, the company that operates the Gaylord National, in an email to CNBC, contradicted Matt Schlapp's claim.

"It is my understanding that no screens of either people or facilities has been performed at the property," Sitch said.

She did say that Marriott has been in contact with local health authorities "and are following their guidance about this situation. "

"We take hotel hygiene and cleanliness very seriously and have already taken a number of additional steps to perform enhanced cleaning of areas of the hotel where the conference was hosted," she said.

At a meeting Monday of hundreds of Gaylord National workers, the hotel's general manager "was flat out asked if that was true" that thousands of screenings had been performed at the hotel on the heels of CPAC, one of those workers told CNBC.

"And he [the manager] said, 'No,'" the worker said. "According to the general manager there's been no sort of mass screening of employees ... he flat out denied it."

A health official from Prince George's County, Maryland, who was also present at that meeting, said he "did not have any knowledge that the state of Maryland had screened thousands of employees" at the hotel, the worker said.

A spokesman for the Maryland Health Department said in an email, "I don't have any information on this," when first asked if any coronavirus screening was done at the Gaylord National.