Special counsel Robert Mueller has submitted material about former National Security Adviser Michael Flynn's questioning by the FBI. U.S. District Court Judge Emmet Sullivan ordered Mueller to turn over by Friday at 3 p.m. all documents related to Flynn's questioning, days before he is to be sentenced on Tuesday.

"Nothing about the way the interview was arranged or conducted caused the defendant to make false statements to the FBI on January 24," the special counsel wrote in the memo. Flynn's attorneys pointed out in their sentencing memo that he had not been warned that lying to the FBI was a crime before he was interviewed by agents.

"A sitting National Security Advisor, former head of an intelligence agency, retired Lieutenant General, and 33-year veteran of the armed forces knows he should not lie to federal agents. He does not need to be warned it is a crime to lie to federal agents to know the importance of telling them the truth," the memo said.

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"The interviewing agents did not observe indicia of deception and had the impression at that time that the defendant was not lying or did not think he was lying...Members of the Presidential Transition Team were likewise misled by the defendant's false denials," the special counsel said. "Those misimpressions do not change the fact-as the defendant has admitted in sworn testimony to this District Court-that he was indeed lying, and knowingly made false statements to FBI agents in a national security investigation."

Read the special counsel's memo here:

The special counsel also attached FBI 302 memos which Flynn's attorneys cited as proof that the FBI did not give him any notice at their first meeting that he should not lie to them. However, the special counsel showed through the 302s that "during the interview, the FBI agents gave the defendant multiple opportunities to correct his false statements by revisiting key questions."

On Jan. 24, 2017, Deputy FBI Director Andrew McCabe called Flynn at his White House office to say he thought that two agents should "sit down" alone with Flynn to talk about his contacts with "Russian representatives," according to the sentencing memo submitted by Flynn's lawyers Wednesday. McCabe told Flynn that if he wanted to include anyone else, like the White House counsel, McCabe would have to bring in the Justice Department. Flynn agreed just to meet with the agents, one of whom was Peter Strzok, who worked on the Mueller Russia probe until it was discovered that he had exchanged text messages critical of President Trump with another FBI official, Lisa Page.

In the course of their interview, Strzok and the agent with him did not inform Flynn that it was a crime to lie to the FBI. They "wanted him to be relaxed," in hopes that he would give them more information. Strzok was fired in August.

In describing his meeting at the White House with Flynn, the 302 memo describes him as "relaxed and jocular," giving them a tour around his office. Apparently, the President and some movers were there while they were taking a tour, "discussing where to place some art work walked between Strzok and [redacted], but nobody paid attention to the agents. Flynn did not introduce them to anyone."

Flynn was apparently very "talkative, and had so much time for them, that Strzok wondering if the National Security Adviser did not have more important things to do than have such a relaxed, non-pertinent discussion with them."

Mr. Trump has been critical of the special counsel's investigation into Flynn, saying on Twitter on Thursday that the special counsel's office "gave General Flynn a great deal because they were embarrassed by the way he was treated."

"They want to scare everybody into making up stories that are not true by catching them in the smallest of misstatements. Sad!" Mr. Trump wrote.

The special counsel's office filed a sentencing memo for Flynn last week, recommending that he receive zero to six months of incarceration due to his "substantial assistance" in the investigation. Flynn met with the special counsel 19 times as part of his agreement to cooperate with the government in its investigation into Russian meddling in the 2016 presidential election. According to the filing, Flynn has been cooperating in "several ongoing investigations."

Although descriptions of his cooperation with Mueller's team are redacted, they acknowledge Flynn assisted government investigators on a "range of issues, including interactions between individuals in the Presidential Transition Team and Russia."

Flynn's attorneys filed a sentencing recommendation Tuesday calling for a sentence of probation and community service, sparing him prison time out of respect for his decades of military service and his "genuine contrition for the uncharacteristic error in judgment that brought him before this court."

Clare Hymes contributed to this report.

This is a developing story and will be updated.