In earlier tweets, the president also berated former Federal Bureau of Investigation deputy director Andrew McCabe, who was fired by Attorney General Jeff Sessions on Friday just two days before he was due to retire, and former Federal Bureau of Investigation director James Comey, whom Mr Trump sacked a year ago.
President Donald Trump on Sunday questioned the impartiality of special counsel Robert Mueller's investigation and raised doubts about whether a fired top FBI official kept personal memos outlining his interactions with Trump. "As many are now finding out, however, there was tremendous leaking, lying and corruption at the highest levels of the FBI, Justice & State." - tweet Saturday.
In a statement Friday night, McCabe hit back, saying his firing is part of a larger effort to discredit the FBI and the special counsel's investigation into Russian meddling in the 2016 election.
McCabe began working at the FBI's NY field office in 1996, was promoted to a supervisor position at the FBI's headquarters in 2006, and held various jobs at the bureau until 2016, when he was named deputy director.
And Republicans on the House Intelligence Committee said this past week that they had completed a draft report concluding, after a yearlong investigation, that there was no collusion or coordination between the Trump campaign and Russian Federation; committee Democrats vehemently disagreed. President Donald Trump has accused McCabe of receiving money from Hillary Clinton.
Trump claimed Comey lied in that interaction. But Mueller continues to explore whether collusion occurred and whether Trump or others may have obstructed justice.
This is all very ominous, unquestionably a threat, and also makes one wonder if Brennan and Power are receiving unauthorized information, possibly from Robert Mueller's special counsel office.
Jonathan Turley, a law professor at George Washington University, appeared on CNN Saturday to talk about former FBI Deputy Director Andrew McCabe's firing just days before he was set to retire. Rosenstein serves under Attorney General Jeff Sessions, a Trump appointee to the Cabinet. Host Maria Bartiromo noted that 10 people "at the top of the FBI and the Department of Justice" have been "either fired or reassigned" over the last several months as details about the Clinton investigation and the investigation into Russian Federation and Trump's presidential campaign came to light.
After reports that Mueller had the memos, Trump tweeted, "Spent very little time with Andrew McCabe, but he never took notes when he was with me".
Lost in all the hubbub is that McCabe was sacked for allegedly authorizing the leaking of sensitive information to a reporter and then misleading investigators when asked about it.
Mr Comey has testified that Mr Trump had asked him for his "loyalty" and requested he drop an inquiry into his disgraced former National Security Adviser Michael Flynn.
Trump's complaint, as he spelled it out in the past, is that Clinton-linked money went to "the wife of the FBI agent who was in charge of her investigation".
"And I have never been so concerned that the walls meant to protect the independence of our dedicated law enforcement professionals, including special counsel Mueller, are at risk of crumbling".
Mr McCabe had been under internal investigation by the FBI and had already stepped down from his deputy post in January pending the review.
Trump and Sessions have both received backlash over the firing of McCabe.