Former FBI Deputy Director Andrew McCabe, who was fired by Attorney General Jeff Sessions last week, himself oversaw a criminal investigation into Sessions’ testimony to Congress in early 2017, ABC News first reported Wednesday.

Citing unnamed sources familiar with the matter, ABC News reported that McCabe authorized the investigation after then-FBI Director James Comey received a letter from Sen. Patrick Leahy (D-VT) and then-Sen. Al Franken (D-MN) in March of last year regarding Sessions’ contacts with Russians. McCabe served as acting FBI Director in between Trump’s firing of Comey in May and the confirmation of current Director Christopher Wray in August.

In January, during his confirmation hearing before the Senate Judiciary Committee, Sessions said he had not had contacts with Russians during the 2016 campaign.

The Washington Post revealed in March that the claim was not true: Sessions had met twice with Russia’s then-ambassador to the United States during the campaign.

One unnamed source told ABC News that Sessions was not aware of the probe when he fired McCabe last week for McCabe’s lack of “candor – including under oath – on multiple occasions” during an inspector general’s investigation. (McCabe denies wrongdoing and has said his firing was due to his potential as a witness in special counsel Robet Mueller’s probe.)

Sessions’ lawyer did not confirm that he lacked awareness of the probe into his actions, the outlet said. The lawyer did say the FBI probe of Sessions’ testimony was closed.

“The Special Counsel’s office has informed me that after interviewing the attorney general and conducting additional investigation, the attorney general is not under investigation for false statements or perjury in his confirmation hearing testimony and related written submissions to Congress,” Sessions’ attorney, Chuck Cooper, told ABC News.

The outlet said it “was told” that top Republicans and Democrats in Congress were informed of the investigation of Sessions by Deputy Attorney General Rod Rosenstein and McCabe “last year,” after the March revelations and Sessions’ subsequent recusal from matters relating to Russian election interference.

ABC News noted that Mueller interviewed Sessions two months ago as part of his probe, and that it is unknown whether Mueller may be pursuing other leads related to Sessions.