Revelations in the investigation into the Russia probe's origins “are stunning,” Sen. Ron Johnson, R-Wis., told “Sunday Morning Futures,” adding that “we should have known” about them “years ago.”

Johnson, who is conducting his own deep dive into Obama-era corruption, made the comments two days after Fox News has learned, according to two sources close to the matter, that former FBI lawyer Kevin Clinesmith will plead guilty to making a false statement in the first criminal case arising from U.S. Attorney John Durham’s review of the investigation into links between Russia and the 2016 Trump campaign.

Johnson, who is the chairman of the Committee on Homeland Security and Governmental Affairs, reacted to Clinesmith’s expected plea on Sunday saying, “this is an obvious indictment, and I can only assume the reason it took so long is probably John Durham was trying to get Kevin Clinesmith to cooperate with his additional prosecutions and investigations.”

“I’m hoping that’s the case because there’s an awful lot of wrongdoing that has to be exposed,” Johnson continued.

He then explained what he thinks is “probably most stunning about the court document.”

RUSSIA 'ORIGINS' PROBE TO YIELD 'SIGNIFICANT DEVELOPMENTS,' BARR SAYS

“Now we know that back in August of 2016, the CIA had already notified the FBI that they knew [former Trump campaign aide] Carter Page was an operational contact for the CIA, so the FBI knew this back in August of 2016, and we only know that now,” Johnson said.

”What we found out in just the last week, you know the pre-meditated lie on the part of the FBI briefers to the Senate Intelligence Committee, now the fact that the FBI knew that Carter Page was an operational contact back in August 2016. These revelations are stunning, and we should have known about this years ago.”

Johnson went on to say that the revelations make him “even more frustrated” with FBI Director Christopher Wray to the point where he was “forced to issue him a subpoena.

Last week, the Senate Homeland Security Committee subpoenaed the FBI and Wray as part of its broad review into the origins of the Russia investigation.

The FBI must provide these documents to the committee by Aug. 20 at 5 p.m. ET, according to the subpoena.

Johnson told host Maria Bartiromo on Sunday that those documents “better be forthcoming.”

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“Now we know there was absolute corruption at the highest levels of the FBI, and it’s taken years for this to come out,” Johnson said. “This is completely unacceptable. We need to get to the truth as quickly as possible.”

Fox News’ Brooke Singman contributed to this report.