Acting Inspector General Charles Sheehan is out to get EPA Chief of Staff Ryan Jackson, Mandy Gunasekara, a former official with the agency's air and radiation department, told the DCNF on Friday. Sheehan told Congress in October that Jackson is refusing to participate in ongoing probes.

"It is very telling. It's just an attempt to embarrass Ryan. Make a big public spectacle. This is the way the deep state works," Gunasekara said. She was referring to Sheehan's probe of Jackson's alleged efforts to pressure a former agency scientist ahead of her congressional testimony.

"To countenance open defiance even in one instance — much less two, both by a senior official setting precedent for himself and all agency staff — is ruinous," Sheehan wrote in the Oct. 29 letter.

EPA officials said Jackson did the best he could to provide documentation to Sheehan.