Sen. Ron Johnson, R-Wis., the chairman of the Senate Homeland Security Committee, said on Sunday that he saw “total corruption” in the transition between the presidency of Barack Obama and that of Donald Trump.

Speaking on “Sunday Morning Futures,” Johnson called the investigation into Russian interference in the 2016 “corrupt” and slammed the media for reporting on leaked information.

“What we saw was a total corruption that before, during and after this transition. It's incredibly serious,” Johnson said. “What we know is corrupt investigations, the misuse of defensive briefings, all the media leaks, and, of course, the Obama administration holdovers.

SENATE JUDICIARY COMMITTEE TO VOTE ON SUBPOENAS IN REVIEW OF RUSSIA PROBE

He added: “What they did once they're inside the Trump administration to frustrate and sabotage his administration. So this is a serious, serious internal attack, an assault on our democracy, the most serious possibly in our history.”

Johnson’s comments come just days after his committee announced it was considering subpoenas for records and testimony from current and former FBI officials involved in the bureau’s original Russia investigation, as investigations into the origins of that probe ramp up again on Capitol Hill.

Fox News learned that Johnson is seeking authorization to issue subpoenas next Thursday for documents and testimony related to the FBI’s “Crossfire Hurricane” investigation, the Justice Department inspector general’s review of that investigation, and the “unmasking” of U.S. individuals affiliated with the Trump campaign, transition teams and the Trump administration.

“Crossfire Hurricane” was the FBI’s internal code name for the bureau’s original investigation, beginning in July 2016, into whether members of the Trump campaign were colluding with Russia to influence the 2016 presidential election. That investigation was launched by the FBI in July 2016. Former special counsel Robert Mueller's team eventually announced that it found no evidence of illegal coordination.

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Johnson earlier this month requested from the intelligence community the declassification and release of any unmasking files related to members of the Trump family, Trump campaign and Trump administration.

Johnson has scheduled the “business meeting” to consider authorizing subpoenas for June 4 — the same day that the Senate Judiciary Committee, chaired by Sen. Lindsey Graham, R-S.C., will also vote to authorize subpoenas as part of their investigation.

“We have a list of 35 people currently,” Johnson said Sunday. “It's very similar to what Lindsey Graham is going to be working on as well. We're not going to. There'll be some overlap, but we'll kind of let Lindsey Graham focus on the FBI, the Department Justice or the corruption that FISA process.

He added: “We'll be listening very carefully to his hearings and probably calling in those witnesses for follow up questions.”

Fox News’ Brooke Singman contributed to this report.