Newly released FBI documents detailing the bureau’s investigation of former Secretary of State Hillary Clinton’s emails reveal the aide who would likely follow her into the White House as chief counsel was central to a coverup of evidence sought by investigators.

Yet despite signs that Clinton’s former chief of staff Cheryl Mills obstructed efforts by investigators to obtain Clinton’s emails, the FBI invited Mills to attend Clinton’s interview at FBI headquarters as one of her lawyers.

“It’s absolutely outrageous,” Judicial Watch president Tom Fitton said.

“The FBI saw massive document destruction and clear intent to withhold material evidence,” he added, “and they just ignored that obstruction, and even let her sit in on the interview.”

The smoking gun is on Page 16 of the FBI’s 47-page report. It details how Mills ultimately made the determinations about which emails should be preserved before she and Clinton decided to delete the rest as “personal.” Clinton conducted both government and personal business using a personal email account — clintonemail.com — tied to an unsecured server set up in the basement of her New York home.

The FBI makes clear the procedure Mills used to sort out the emails was suspicious.

For starters, Mills was the one who ordered the server host to move the emails from the server to a laptop where she could screen them. She told investigators she could “not recall” if emails with non-gov addresses were included in the transfer. It’s unlikely they were, because an aide who helped her search told the FBI she only screened for emails sent to or from Clinton with .gov and .mil — not .com — addresses.

That means messages involving government business between Clinton and her then-deputy chief of staff Huma Abedin — the only aide who had an email account on the clintonemail.com system— were not likely captured. Nor were messages sent between Clinton and Mills and other aides using personal email addresses.

‘The FBI saw massive document destruction and clear intent to withhold material evidence and they just ignored that obstruction, and even let [Mills] sit in on the interview.’ - Tom Fitton, Judicial Watch president

Correspondence between Clinton and Abedin (who regularly emailed her boss from huma@clintonemail.com and HAbedin@hillaryclinton.com) is crucial, Fitton says, because Abedin acted as the go-between on requests for access to Clinton from shady foreign Clinton Foundation donors. He says the mushrooming “pay-for-play” scandal is the real reason the former secretary of state set up a private email system in the first place.

“The whole thing was designed to keep Clinton Foundation emails away from investigators,” he said.

And Mills may have been a key player in the game of hide-and-seek.

“It was clear they did not want non-.gov-related emails picked up in their search, so they said, let’s search in a way that those emails won’t be picked up; and if they are picked up, we’ll have Mills come in and shred them,” Fitton said.

Indeed, the FBI said Mills “shredded” any copies of emails she “deemed not to be work-related” before they were turned over to State in response to requests for information from Judicial Watch, the media, Congress and the FBI. The laptop hard drive was later wiped clean using a computer program called BleachBit.

The FBI said it was “unable to obtain a complete list of keywords or named officials searched,” because Mills asserted that such information was “privileged.” In fact, when agents pressed her, Mills stormed out of the room and ended the interview. Curiously, the FBI honored her claim of privilege and did not pursue the matter.

“Mills did not do a proper search of the server,” Fitton asserted. “The evidence was just essentially shredded.”

He added that Mills and a State aide who assisted her in conducting the dubious search — Heather Samuelson, a loyal Clinton campaign worker — had a vested interest in covering up email evidence.

“They were State Department employees and were completely conflicted in conducting that search,” he said.

As participants in the activities under investigation, Mills and Samuelson should have been key FBI targets, yet both appeared at Clinton’s FBI interview with her phalanx of lawyers, allowing them insights into the investigation.

Fitton said their attendance was highly unusual, but not surprising. He said it was just one more sign the fix was in with the FBI’s investigation of Clinton’s emails: “It’s the Keystone Kops approach to investigating.”

Sperry is author of “The Great American Bank Robbery,” which exposes how liberal Clinton housing policies led to the mortgage crisis.