An former FBI agent hired to investigate Eric Greitens, a Navy SEAL veteran who was Missouri governor, has been indicted on perjury charges.

William Tisaby was charged with six counts of perjury and one count of tampering with physical evidence in the indictment, which was unsealed Monday. He had been under investigation by a special counsel charged with looking into allegations that he lied during a 2008 hearing.

Tisaby, 66, was hired by St. Louis Circuit Attorney Kim Gardner days after Greitens, a 45-year-old Republican, admitted to having an affair with a hairdresser in 2018. He was tasked with looking into allegations that Greitens took a photo of a partially nude woman in 2015 and was using it as blackmail, threatening to release the picture unless she kept quiet about the affair.

The indictment says that Tisaby lied under oath about “matters which could substantially affect, or did substantially affect, the course or outcome of the Greitens case.” He was accused of tampering with evidence for allegedly keeping documents in the case from Greitens' defense attorneys.

In May last year, prosecutors dropped a felony invasion-of-privacy charge against Greitens, a former Rhodes scholar. Despite that, Greitens ended up resigning last June.

Greitens’ former lawyer Scott Rosenblum tore into prosecutors, accusing them of misconduct in last year’s highly publicized case.

“Eric Greitens should still be governor,” Rosenblum said. “This was a misguided prosecution from the very beginning. It’s one of the worst cases of prosecutorial misconduct that I have seen in my 36 years of practicing criminal defense law.”

Gardner’s office remains under investigation by the special counsel.