Meanwhile, Flynn's lawyers informed the White House it would no longer discuss the Mueller investigation with the Trump administration's legal team, according to The New York Times. They had been sharing information up until this point.
In August, The Wall Street Journal reported that Mueller was investigating whether Flynn tried to obtain Hillary Clinton's deleted emails from Russian hackers.
Jay Sekulow, a member of Trump's legal team, said that the decision to no longer share information "is not entirely unexpected" and shouldn't be seen as an indication of cooperation.
President Donald Trump again derided the National Football League on Friday amid news one of his former top official has cut off ties with the president's lawyers.
Two congressional officials involved in separate probes into the Trump campaign's contacts with Russian Federation said one key area of investigation is whether Flynn or other advisers to Trump ever suggested USA economic sanctions on Russian Federation could be lifted in exchange for favorable business deals.
Months later, the company admitted in documents filed under the Foreign Agents Registration Act (FARA) that their work 'could be construed to have principally benefitted the Republic of Turkey'.
Flynn was subject to questions and scrutiny during his brief stint as the White House national security adviser over phone calls with the former Russian ambassador to the US, Sergey Kislyak. But, according to the Times, it signals that Flynn is at least discussing the option with prosecutors.
Mr. Flynn is regarded as loyal to Mr. Trump, but he has in recent weeks expressed serious concerns to friends that prosecutors will bring charges against his son, Michael Flynn Jr., who served as his father's chief of staff and was a part of several financial deals involving the elder Mr. Flynn that Mr. Mueller is scrutinizing.
So far three Trump campaign officials have been charged, including former chairman Paul Manafort, aide Rick Gates and foreign policy advisor George Papadopoulos, who has pleaded guilty.