Sources say he could draw in senior transition team members, the Trump family, even the President himself.
The 58-year-old Flynn - a retired three-star Army general - is the fourth, and so far most senior, figure indicted in the sprawling investigation into Russian interference in last year's election.
As part of Flynn's plea deal he agreed to "cooperate fully, truthfully, completely, and forthrightly" with the special counsel's office.
In the second statement Flynn made on December 22, 2016, Flynn denied asking a Russian Ambassador to delay or defeat a United Nations Security Council resolution.
ABC suggests Flynn could testify that Trump directed him to make contact with Russian operatives during the campaign; meanwhile, a report by NBC suggests Jared Kushner could be a person of interest in the investigation by Robert Mueller's team.
President Donald Trump's former national security adviser Michael Flynn released a statement following the news that he has been charged with making false statements to federal investigators about his conversations last December with Russia's ambassador to the U.S. at the time, Sergey Kislyak.
USA stock markets tumbled on Friday - before creeping back up - upon news that President Donald Trump's former national security adviser Michael Flynn would plead guilty to providing false statements to the Federal Bureau of Investigation, as part of the ongoing probe into Trump's campaign ties to Russian Federation.
The retired US Army Lieutenant General was specifically accused of lying about a conversation he had with Kislyak concerning sanctions that then-US President Barack Obama imposed on Russian Federation in late December 2016. They also extend to false statements that Flynn made in regard to his company, the Flynn Intel Group, in connection with his work as a lobbyist and consultant to the government of Turkey. "I accept full responsibility for my actions".
The Obama administration, in a rare step that shocked its Middle East ally, planned to abstain on the motion rather than veto it as had been done in the past.
Sally Yates, the acting attorney general, goes to the White House and warns White House counsel Donald McGahn that Flynn has misled administration officials about his contacts with Kislyak and is potentially subject to Russian blackmail. His business dealings and foreign interactions have made him a central focus of Mueller's investigation.
Trump ignored reporters' shouted questions as he welcomed the Libyan prime minister to the White House, and aides canceled media access to a later meeting between the two.
"Since the first day I took office, all you hear is the phony Democrat excuse for losing the election, Russia, Russia, Russia", he tweeted last week.
The charges against Flynn stem from Mueller's months-long investigation into purported Russian meddling to influence the outcome of the 2016 presidential election, including hacking the computers of the Democratic National Committee, and into any possible collusion between Russia and the Trump campaign.