Former national security adviser Michael T. Flynn leaves federal court in Washington. (Susan Walsh/AP)

An official with a company that former national security adviser Michael T. Flynn advised on a proposal to build nuclear power plants in the Middle East denied that Flynn communicated with the firm's managing director about the project on Inauguration Day.

Thomas B. Cochran, senior scientist at ACU Strategic Partners, described the charges by a congressional witness as "patently false and unfounded" in a letter sent Friday to Rep. Elijah E. Cummings (Md.), the ranking Democrat on the House Committee on Oversight and Government Affairs.

Last week, Cummings released the account of the witness, who said that Alex Copson, ACU's managing director, claimed he received a text message from Flynn during President Trump's inaugural address telling him that the nuclear plan was "good to go."

Flynn had also assured Copson that U.S. sanctions against Russia would immediately be "ripped up" by the Trump administration, a move that would help facilitate the deal, Copson claimed, according to the witness.

Cochran wrote in his letter to Cummings that the firm had examined Copson's mobile phone bill and found no text messages from Flynn, an absence he said contradicted "the core allegation" of the witness.

In an interview Monday, Cochran added that Copson did not have an encrypted texting app or any other means of receiving texts. Asked whether Copson would agree to an interview by committee officials, Cochran said that "we would be receptive to briefing the full committee if requested."

Flynn, who briefly served as Trump's national security adviser before being fired, has said he was an adviser to ACU and traveled with company officials in 2015 to Egypt and Israel to promote their plan to build nuclear power plants.

Cummings said in a Monday letter that he wanted Copson to agree to a transcribed interview to explore the matter, noting it was possible that Copson was "not being truthful" during his exchange with the witness on Inauguration Day.

While Cummings has sought support from Republicans on the committee for such a briefing, GOP Chairman Trey Gowdy of South Carolina has denied the request, and has instead forwarded the information to special counsel Robert S. Mueller III.

Flynn's lawyer, Robert Kelner, declined to comment. Flynn pleaded guilty this month to lying to FBI agents about his interactions with the Russian ambassador to the United States.