Democrats on the House Oversight Committee said Wednesday a whistleblower approached them in June to share that former national security adviser Michael Flynn had texted him during President Trump's inauguration to tell his former business partners that a ploy to build a number of nuclear reactors in the Middle East, with Russia's help, was "good to go," according to multiple reports Wednesday.

The group of Democrats said they received a letter Wednesday from an anonymous informant who said he attended an inauguration day event with one of Flynn's business partners. The whistleblower attended the event with Alex Copson, a managing partner of ACU Strategic Partners.

"Our committee has credible allegations that President Trump's National Security Advisor sought to manipulate the course of international nuclear policy for the financial gain of his former business partners," Rep. Elijah Cummings, ranking Democrat on the House oversight committee, wrote to Chairman Trey Gowdy, R-S.C. "These grave allegations compel a full, credible, and bipartisan congressional investigation."

In a text message sent at 12:11 p.m. EST, the source said Copson showed him a message that Flynn would have sent from his chair in the dais while Trump addressed the country.

Copson's friend recalled him saying it was "the best day of my life" after being told his company's plan to forge a U.S.-Russia partnership and build two dozen nuclear plants was moving forward.

Cummings said the whistleblower first approached the committee in June, but special counsel Robert Mueller asked him to "hold on the public release of this information until they completed certain investigation steps."

Cummings told Gowdy "they have now informed us that they have done so."

Flynn reportedly bragged about his partners' business plan and worked to promote the plan even as a White House official.

Flynn pleaded guilty last week to lying to the FBI about when he contacted Russian officials before Trump was sworn into office.