President Trump on Thursday pressed Senate Judiciary Committee Chairman Lindsey Graham to call former President Barack Obama to testify amid new developments surrounding the origins of the Russia investigation and efforts at the time to "unmask" Michael Flynn's name in intelligence reports.

“If I were a Senator or Congressman, the first person I would call to testify about the biggest political crime and scandal in the history of the USA, by FAR, is former President Obama,” Trump tweeted Thursday. “He knew EVERYTHING.”

GRAHAM TO SEEK TESTIMONY FROM TOP OBAMA OFFICIALS ON RUSSIA PROBE, COULD ISSUE SUBPOENAS

“Do it @LindseyGrahamSC, just do it,” he continued. “No more Mr. Nice Guy. No more talk!”

An error occurred while retrieving the Tweet. It might have been deleted.

The extraordinary demand comes as Trump has increasingly sought to link his predecessor to efforts to investigate his associates in 2016 and 2017, dubbing it "Obamagate." The tweet comes after Sens. Chuck Grassley, R-Iowa, and Ron Johnson, R-Wis., made public a list of Obama officials who purportedly requested to “unmask” the identity of Flynn, who at the time was Trump’s incoming national security adviser.

The list was declassified by Acting Director of National Intelligence Richard Grenell and sent to Grassley and Johnson.

The roster featured top-ranking figures including then-Vice President Joe Biden, then-FBI Director James Comey, then-CIA Director John Brennan, then-Director of National Intelligence James Clapper, and Obama’s then-chief of staff Denis McDonough.

But Graham, in a detailed statement early Thursday afternoon, expressed reluctance to go so far as calling Obama to testify.

He said he is "greatly concerned about the precedent that would be set by calling a former president for oversight."

"No president is above the law," Graham said in the statement. "However, the presidency has executive privilege claims against other branches of government. ... As to the Judiciary Committee, both presidents are welcome to come before the committee and share their concerns about each other. If nothing else it would make for great television. However, I have great doubts about whether it would be wise for the country.”

Nevertheless, Graham said that his panel will “begin holding multiple, in-depth congressional hearings regarding all things related to Crossfire Hurricane starting in early June.”

Crossfire Hurricane was the FBI’s internal code name for the investigation into whether members of the Trump campaign were coordinating or colluding with Russia during the 2016 presidential election.

The president, earlier Thursday, blasted the Obama administration over the unmasking revelations and claimed that "it was the greatest political crime in the history of our country."

"If I were a Democrat instead of a Republican, I think everybody would have been in jail a long time ago, and I'm talking with 50-year sentences. It is a disgrace what's happened. This is the greatest political scam, hoax in the history of our country," Trump said during an exclusive interview Thursday with Fox Business' Maria Bartiromo. "People should be going to jail for this stuff and hopefully, a lot of people are going to have to pay."

As Fox News previously reported, Grenell had made the decision to declassify information about Obama administration officials who were involved in the “unmasking” of Flynn — whose calls with the former Russian ambassador during the presidential transition were picked up in surveillance and later leaked. His case has returned to the national spotlight after the DOJ moved to dismiss charges against him of lying to the FBI about those conversations, despite a guilty plea that he later sought to withdraw.

The declassified list, released Wednesday, specifically showed officials who “may have received Lt. Gen Flynn’s identity in response to a request processed between 8 November 2016 and 31 January 2017 to unmask an identity that had been generically referred to in an NSA foreign intelligence report,” the document said.

LIST OF OFFICIALS WHO SOUGHT TO 'UNMASK' FLYNN RELEASED: BIDEN, COMEY, OBAMA CHIEF OF STAFF AMONG THEM

“Each individual was an authorized recipient of the original report and the unmasking was approved through NSA’s standard process, which includes a review of the justification for the request,” the document said. “Only certain personnel are authorized to submit unmasking requests into the NSA system. In this case, 16 authorized individuals requested unmasking for [REDACTED] different NSA intelligence reports for select identified principals.”

The document added: “While the principals are identified below, we cannot confirm they saw the unmasked information. This response does not include any requests outside of the specified time-frame.”

Officials requesting such a name in this process do not necessarily know the identity in advance.

In a statement on Wednesday, Andrew Bates, Biden's director of rapid response, downplayed the latest Flynn revelations.

"These documents have absolutely nothing to do with any FBI investigation and they confirm that all normal procedures were followed -- any suggestion otherwise is a flat out lie,” Bates said. “What's more, it's telling that these documents were selectively leaked by Republicans abusing their congressional powers to act as arms of the Trump campaign after having them provided by a partisan official installed for this very purpose.”

Meanwhile, Graham said earlier this week that he wants to know "how many unmasking requests were made, if any, beyond General Flynn regarding members of the Trump campaign team, family, or associates."

Graham has been leading his committee's investigation into the origins of the Russia investigation for months. A source told Fox News this week that the committee is considering inviting Brennan, Clapper and Deputy Attorney General Sally Yates to testify before the committee.

TRUMP WEIGHS IN ON UNMASKING: 'GREATEST POLITICAL CRIME IN THE HISTORY OF OUR COUNTRY'

The source told Fox News that the committee would invite the ex-officials to appear but would subpoena them if they encounter resistance. The source told Fox News that Senate investigators are looking at “various pieces” coming from “various sources” as part of their investigation.

“This is a multilevel puzzle,” the source said. “They are looking at layer upon layer, and you have to be able to tell the story of exactly what was going on, and who was doing what, when, and why.”

Officials in the Obama administration have acknowledged that they moved to unmask some Americans in intelligence reports, but insisted that their reasons were legitimate. Thousands of unmasking requests have been made during both the Obama and Trump administrations, complicating any efforts to determine if certain requests may have been somehow improper.