Late Saturday, Mueller's spokesman, Peter Carr, said the special counsel's office has followed the law when it has obtained documents during its investigation.
How it happened: The sources say Mueller obtained the emails from the General Services Administration, the government agency that hosted the transition email system, which had addresses ending in "ptt.gov", for Presidential Transition Team. "I think the American people are ready to turn the page".
Treasury Secretary Steve Mnuchin and Marc Short, White House director of legislative affairs, said Sunday in separate interviews that they were unaware of any such discussions.
Mnuchin's comments come a day after White House special counsel Ty Cobb told CNN in a statement that there are no plans to fire Mueller.
"There's no conversation about that whatsoever in the White House", Short said on "Meet The Press".
"You guys keep bringing that up", he added when pressed on the issue. "We've continued to cooperate at every single possible way with that investigation".
Ted Lieu a Democratic representative for California accused Republican Senator John Cornyn of "partisan talk", when he suggested Mueller must "clean house of partisans" on social media. Trump's legal team has reacted with outraged claims of unconstitutional and illegal tactics, while Fox News hosts have begun wildly accusing the Federal Bureau of Investigation and Mueller of a "coup".
Sen. James Lankford, R-Oklahoma, told CBS's "Face the Nation" on Sunday that the indications of political bias are "very serious", but a distinction should be made about whether Strzok was "directing the investigation one way or another".
Herein lies the possibility of a real "high noon showdown" between Trump and Mueller, with the president insisting that the special counsel limit his probe to matters pertaining to Russian interference in the election and Mueller demanding a broader scope for his investigation. And she speculated that Republicans are trying to shut down the House Intelligence committee's Russian Federation probe.
On whether Mueller should have disclosed that they had obtained the emails, Loewentritt added, "That's between the Special Counsel and the transition team".
Adam Schiff, the ranking Democrat on the House Intelligence Committee, tweeted his own concerns on Friday, saying, "I'm increasingly anxious Republicans will shut down the House Intelligence Committee investigation at the end of the month".
"Of course Mueller obtained emails from a third party", Renato Mariotti, a former federal prosecutor, said, also on Twitter.
Mueller recently removed an FBI official from the investigation as soon as his anti-Trump text messages were discovered.
On Friday, the President was asked by a reporter if he thought Mueller's team was biased. If this report bears out, then they are going to demand a return.