Michael Flynn promised a former business partner that Obama-era sanctions against Russian Federation would be "ripped up" once the Trump administration assumed power, according to a whistleblower whose account was released Wednesday by congressional Democrats.
In June, the whistleblower first contacted Cummings and gave the congressman permission to share the account as part of the ongoing investigation into Russia's meddling in the 2016 presidential election.
The whistleblower also said that within minutes of Trump's inauguration ceremony, Flynn communicated directly with business associates about plans to begin building nuclear reactors in the Middle East-a joint project with Russian Federation, according to the letter.
According to a letter by Rep. Elijah Cummings of Maryland, Copson then showed the whistleblower his phone, which contained a message from Flynn.
The witness told congressional investigators that he was "extremely uncomfortable" with the conversation, Cummings wrote, and took brief notes about the discussion during the inaugural event.
Flynn allegedly sent the messages to Alex Copson, managing partner of ACU Strategic Partners, a United States nuclear power consultancy.
He also said he finds the whistle-blower to be "authentic, credible and reliable", and someone who has come forward even though he fears retaliation because "he feels duty bound as a citizen to make this disclosure".
The chairman said he shared Mr Cummings's letter with the Republican leading the Intelligence Committee's Trump-Russia probe, as well as that panel's top Democrat, "so they may determine whether to add witnesses" to that panel's witness list. "This is going to make a lot of very wealthy people".
An attorney for Flynn did not respond to a request for comment from CNBC.
On December 29, the day the Obama administration imposed new sanctions and expelled 35 Russian diplomats from the USA in retaliation for Moscow's election meddling, Flynn called Kislyak and asked that Russia not escalate the situation, according to court documents. On Inauguration Day, according to the whistle-blower, Mr. Flynn texted the former business associate to say that the project was "good to go". Mr Copson was described by the whistle-blower as responding, "I couldn't be better", and that he was "going to celebrate today".
Flynn pleaded guilty last week to lying to the Federal Bureau of Investigation about the nature of his conversations with former Russian ambassador Sergei Kislyak.
Now, Mr Cummings wrote, he and his colleagues have been authorised to to go public with the information.
"Mike has been putting everything in place for us", Copson said, according to the whistleblower. The witness could not read the text, but he saw that the time stamp was 12:11 p.m., according Cummings's letter.
The whistleblower told Democrats that the associate had been informed by Flynn that the project was "good to go" and that the sanctions would be "ripped up". Now Cummings wants to look into the matter.