Mueller's team is also examining whether Flynn attempted to orchestrate the removal of a chief rival of Turkish President Recep Erdogan from the U.S.to Turkey in exchange for millions of dollars, two officials said.
The report comes after Mr. Mueller handed out "quickened" aggrssive and flawed indictments involving money laundering and tax fraud to former Trump Campaign Chairman Paul Manafort and his business associate Rick Gates, incitements that were filed 3 day before the statute of limitation would have foreclosed them.
The elder Flynn served in his role at the White House for only 24 days before being fired for misleading Vice President Mike Pence and several others about conversations he had with Russian Ambassador Sergey Kislyak.
It seems some in Washington weren't surprised by reports signaling Trump's former national security adviser may be the next person to face charges in Mueller's prove.
If Mueller does charge Flynn it would be a milestone because it would mark the first time that a current or former Trump administration official would be formally charged with committing a crime.
Mr Mueller's team was reportedly intending to interview more witnesses over the next week as it investigates lobbying work by Mr Flynn.
Three House Republicans have said "obvious conflicts of interest" should require Mueller to step down, citing his relationship with former Federal Bureau of Investigation director James Comey, Politico reports. The younger Flynn's lawyer, Barry Coburn, declined to comment.
The alleged evidence against Mr Flynn, a retired army general, suggests Mr Mueller's probe is getting closer to the inner circle around Mr Trump. It remained unclear Sunday if Mueller had plans to pursue charges against Flynn or his son. It was also revealed last week that former foreign policy adviser for the Trump campaign, George Papadopoulos, had pleaded guilty to lying to the F.B.I.