After the release of the letter, Rep, Jason Chaffetz, R-Utah, chairman of the House Oversight Committee, formally requested that the secretary of the Army make a final determination on whether Flynn broke the law and, if he has, then initiate the process to get Flynn to repay the money.
As a result, Cummings said, the U.S. Defense Department has opened its own investigation into Flynn allegedly receiving payment from a foreign government.
WASHINGTON (AP) Investigations intensified into President Donald Trump's ousted national security adviser, Michael Flynn, on Thursday as the Pentagon watchdog joined lawmakers in probing payments he accepted from foreign sources including a Russian state-sponsored TV network. But on Thursday Elijah Cummings, the committee's vice chair, said the DIA informed the committee that there is no evidence that Flynn requested approval to take the money from RT, which the USA says is an arm of the Russian government.
Spicer said the White House has "complied with every document they have looked for" and that the information the committee is seeking is from before Trump took office. So the issue is - he was issued a security clearance under the Obama administration in the spring of 2016.
Last month Flynn's company filed as a foreign agent with the Justice Department for its consulting work and acknowledged the work may have benefited the government of Turkey.
A Pentagon spokesman confirmed that on April 4 the Defense Department's inspector general began an investigation into Flynn's alleged violations of the emoluments clause. He has claimed previously that his client informed officials at the Defense Intelligence Agency, which the retired lieutenant general helmed until his firing in 2014, about the trip to Russian Federation.
The Thursday revelation that Michael Flynn was warned he couldn't take foreign payments came to the House Oversight Committee courtesy of the Department of Defense.
Flynn resigned on February 13 after failing to disclose his talks with Sergei Kislyak, Russian ambassador to the United States, before Trump took office.
In a statement released on Tuesday, Flynn's attorney said Flynn briefed the DIA "extensively" on his 2015 overseas trip to Moscow and he answered questions that were posed by DIA on the trip.
The peril for the Trump administration is that it now faces not just an active FBI investigation, but two major, functioning Congressional probes and additional inquiries - all churning slowly in quiet, digging deeper into the Trump campaign's ties to Russian operatives. "The White House needs to stop making excuses to protect General Flynn".
This is because the US Constitution's Title of Nobility Clause states "no person holding any office of profit or trust under them, shall, without the consent of the Congress, accept of any present, emolument, office, or title, of any kind whatever, from any king, prince, or foreign state" - a clause meant to protect against foreign influence in US government.
"There is a paper trail that White House does not want our committee to follow", Cummings said.
"Flynn later offered to testify to the congressional committees investigating the potential connections between Trump's campaign and Russia's interference in last year's election if he could secure immunity from prosecution", NPR's Phil Ewing reports.