In a letter from Rep. Elijah Cummings (D-Md.) to Rep. Trey Gowdy (R-S.C.), the chairman of the House Oversight Committee, Cummings claims the whistleblower said Flynn messaged a former business colleague, whom he worked with on a project with Russian Federation to "build nuclear power plants in the Middle East", that the plan was "good to go" because the sanctions would be "ripped up" as one of Trump's first acts in office.
Cummings did not identify the witness, whom he described as a whistleblower. It gave Flynn a potential monetary incentive to get sanctions imposed on Russian Federation during the Obama administration lifted immediately.
Cummings also said the whistleblower quoted a business associate of Flynn as saying the economic sanctions against Russian Federation imposed by former President Barack Obama would be "ripped up" as Flynn's first order of business as Trump's national security adviser.
On Friday, Flynn pleaded guilty to lying to Federal Bureau of Investigation agents about conversations he had in December 2016 with the Russian ambassador to the United States about the sanctions, among other topics.
A lawyer for Mr Flynn, who was sacked after only 24 days as Mr Trump's national security adviser, declined to comment.
After getting the texts, Copson said, "Mike has been putting everything in place for us", and, "This is going to make a lot of very wealthy people", Cummings said, quoting the witness. "These grave allegations compel a full, credible, and bipartisan congressional investigation", Cummings wrote in the letter addressed to committee chairman Rep. Trey Gowdy (R-S.C.).
Mr Cummings's letter goes on to relate that during the conversation, Mr Copson told the whistle-blower that he "just got a text message" from Flynn that the project was "good to go" and to contact their business colleagues to "let them know to put things in place".
As the president spoke, Flynn reportedly texted Copson that the nuclear project was "good to go", the witness said Copson told him.
"I believe the American people want Congress to hold President Trump and his administration accountable", Cummings wrote, "and they are exhausted of Republicans in Congress putting their heads in the sand when faced with credible allegations of grave abuses". The whistleblower saw that the time stamp of the message was 12:11 pm, but did not read the text. The whistleblower also said that Copson intimated that USA financial sanctions hobbling the nuclear project were going to be "ripped up".
The office of special counsel Robert S. Mueller III was aware of the witness's account and asked Cummings not to release the information until the special counsel had taken "certain investigative steps", which are now complete, Cummings wrote. Mr. Copson confirmed in a letter to me on June 27, 2017, that his company paid the expenses for a trip General Flynn made to the Middle East in June 2015 to promote his project and provided a $25,000 check to compensate him for the "loss of income and business opportunities resulting from this trip".
Neither Copson nor an attorney for ACU responded to a request for comment.