Flynn hoping DOJ review, or pardon from Trump, will free him from legal purgatory Potential new documents could be latest twist in three-year case.

Lawyers for retired Army Lt. Gen. Michael Flynn said they were given “stunning” evidence from a Justice Department review of former Special Counsel Robert Mueller’s handling of the onetime Trump adviser’s case, but it may not be the total exoneration some anticipate, according to sources familiar with the case.

Some commentators in recent days have been buzzing about documents under protective order in the review of Flynn’s prosecution which they maintain may, if unsealed, be a big step toward clearing the former national security adviser to President Donald Trump, whose criminal case stemming from the Russia probe remains in limbo more than three years after he resigned from the White House.

But while his defense lawyers said in a court filing Friday that the not yet publicly released evidence will help show that their client was “set up and framed” by the FBI, they have not shared any specifics.

"We look forward to the current production being unsealed and more documents produced -- hopefully today,” Flynn attorney Sidney Powell told ABC News Monday. “Our supplement filed Friday reiterates the relief we seek in the interest of justice and as a matter of law.”

Other sources close to Flynn and familiar with the government's production told ABC News the significance of the mystery files is being over-hyped.

For his part, the former Defense Intelligence Agency director returned to Twitter Friday night after two and a half years of silence on social media, posting a “declaration” of his innocence he filed with a federal court in January.

On Saturday, Flynn's family members tweeted a short video of ​the Rhode Island-raised career military intelligence officer after he went surfing on the beaches he grew up on. Flynn, in a black wetsuit and carrying a surfboard, was shown walking home after catching some waves, as he said he has done for the past 55 years.

“Isn’t it funny that this is Purgatory Road?”​ he chuckled to his wife Lori, referring to a roadway near the Middletown beach.

Flynn is still trying to emerge from what his die-hard supporters consider a form of legal purgatory, which is possible through one of three legal avenues: an ongoing Justice Department review of possible misconduct in the FBI investigation of him; proof that his former lawyers guided him into a bad plea deal he acquiesced to in order to spare himself and his son Michael Jr. possible prison time; or a pardon from a vocally sympathetic President Trump.

"We are willing to take this to the very end -- we will keep fighting," said one close confidant of Lt. Gen. Flynn. "If there is a pardon, of course we will take it. We appreciate the President’s sentiments for Gen. Flynn. We will see where it all goes."

Sources with knowledge of the sealed evidence as well as the Flynn ally told ABC News on Monday they expect the files, if revealed publicly, to show that the FBI failed to turn over some records under what's known as the Brady Rule. That requirement is for all potentially exculpatory evidence in the hands of the prosecutors to be turned over to a defendant.

But a full legal exoneration for Flynn is not expected from the sealed records, the sources told ABC News.

The evidence is the first to be used from a review of Flynn’s prosecution ordered by Attorney General Bill Barr earlier this year. The DOJ assigned U.S. attorney for eastern Missouri Jeffrey Jensen to “assist” and review the matter with federal prosecutors in the District of Columbia, whose office has handled Flynn’s case since the special counsel’s office closed up shop a year ago.

“In light of Mr. Jensen's independent review, we are finally getting to the Truth. We applaud Attorney General Barr for directing the proper application of [The Brady Act]," Powell told ABC News Monday.

FBI and Justice Department spokespersons last week denied on the record that FBI Director Christopher Wray or other senior Bureau officials have withheld anything at all.

Speaking to reporters on Sunday, President Trump declined to reveal potential pardons he might make of several former campaign officials convicted in the former special counsel’s probe, only teasing, “you will find out what I'm going to do.”

“I will tell you the whole thing turned out to be a scam and it turned out to be a disgrace to our country, and it was a takedown of a duly elected president. And these people suffered greatly; General Flynn, I mean what they did to him,” Trump added.

Last fall, Flynn posed at D.C. political haunt The Palm with two men who have since benefited from President Trump’s mercy pen: pardoned former NYPD Commissioner Bernie Kerik and embattled Navy SEAL Chief Petty Officer Eddie Gallagher, whose rank and SEAL Trident the president restored and protected.

“The top of the FBI was scum,” Trump also said on Sunday. “And what they did to General Flynn...it was a disgrace. He was in the service for over 30 years. He ends up being a general and respected. And almost his first day in office they come in with papers. They want to investigate him. Never happened before.”

Flynn’s case has had seemingly endless twists and courtroom drama.

After coming under investigation for discrepancies between what the FBI and Justice Department knew of his discussions with Russian Ambassador Sergey Kislyak and his recollections in a meeting with agents right after Trump was sworn in as President, he pleaded guilty in December 2017 to lying to the FBI about his contacts with Moscow's ambassador in Washington and his lobbying filings.

Once a constant companion of Trump on the 2016 campaign trail, amid concerns about Russia’s influence, he was the first of five high-ranking advisers who pleaded guilty in former FBI Director Mueller’s investigation. He offered his cooperation in the probe of Russian meddling and cooperated with prosecutors on multiple cases under the guidance of his former counsel, Rob Kelner.

Flynn reaffirmed his own guilt in a December 2018 sentencing hearing, but the case took another turn when U.S. District Court Judge Emmet Sullivan ripped into the three-star general officer and suggested he should do more before sentencing to prove his cooperation with the government, including in the trial of his former lobbying business partner.

During the subsequent trial of the lobbying partner, Bijan Kian, prosecutors withdrew Flynn as a witness but secured a guilty verdict on Kian anyway -- only to see the trial judge throw it out because he said the government had no proven Kian's guilt.

Prosecutors associated with the former special counsel investigation last year said Flynn hadn't been as cooperative as they earlier had credited him for and, in a switch, they recommended up to six months’ prison time. Flynn, by then having swapped lawyers from the demure Kelner to the dynamic and confrontational Sidney Powell, decided to withdraw his guilty plea this year and allege that Kelner had misled him about the plea deal.

As part of the next strategy to potentially help Flynn's legal troubles, Powell blamed Kelner for the retired general’s criminal conviction, arguing that at the last moment, Flynn was "misled, misinformed and betrayed" by his lawyer and so should be allowed to withdraw his guilty plea for lying to federal agents.

Flynn also insisted he was, in fact, innocent of lying to the FBI agents, explaining that on the day in question, Jan. 24, 2017, he was “extremely busy” four days into his West Wing job but tried his best to answer the agents’ questions about the Russian ambassador and return to his schedule of meetings and briefings.

Powell filed a notice in January announcing Flynn’s intention to withdraw his guilty plea "because of the government's bad faith, vindictiveness and breach of the plea agreement."

In mid-March, in addition to his tweet, ABC News reported Trump was considering a pre-emptive pardon for Flynn, sources familiar with the matter told ABC News.

ABC News Justice reporter Alex Mallin contributed to this report.