The FBI expert in the middle of a political uproar for mocking President Trump in email messages changed a key phrase in former agency Director James Comey’s description of how Hillary Clinton handled classified information, it was reported Monday.

Records show Peter Strzok, who led the investigation of Clinton’s private email server as the second-highest-ranking official in the counterintelligence division, changed Comey’s draft language describing Clinton’s behavior as “grossly negligent” to “extremely careless,” a source told CNN.

The shift from “grossly negligent” to “extremely careless” was key because the federal law that covers how classified material should be handled calls for criminal penalties for “gross negligence.”

Writing the memo was a team effort, with numerous officials weighing in and suggesting changes, sources say.

Senate Judiciary Chairman Chuck Grassley (R-Iowa) questioned the change last month, but the name of the agent who made the edit was not known until now.

Meanwhile, the Daily Caller reported that Strzok interviewed two former Clinton staffers who gave apparently inaccurate statements about her use of a private email server but did not face legal consequences.

Cheryl Mills and Huma Abedin both said they were unaware of Clinton’s server when they were interviewed by Strzok — despite the fact that they were involved in emails that talked about a server.

“Mills did not learn Clinton was using a private server until after Clinton’s [Department of State] tenure,” read notes from Mills’ May 28, 2016, interview, as obtained by the Daily Caller. “Mills stated she was not even sure she knew what a server was at the time.”

Abedin said she didn’t know about Clinton’s server until she left the State Department in 2013.

“Abedin did not know that Clinton had a private server until about a year and a half ago when it became public knowledge,” the summary of Strzok’s interview with Abedin states.

But in an email on Feb. 27, 2010, Mills asked Abedin “hrc email coming back — is server okay?”

During a House Judiciary Committee hearing in September 2016, then-FBI Director Comey defended the conflicting statements.

“Having done many investigations myself, there’s always conflicting recollections of facts, some of which are central [to the investigation], some of which are peripheral,” Comey said.

CNN also reported that Strzok was the FBI official who signed the document that launched the investigation into Russian meddling in the 2016 election.

He was taken off the probe after emails he wrote to another agent apparently mocking Trump came to the attention of special counsel Robert Mueller, who is heading the investigation.

The president took to Twitter over the weekend to slam the agent. “Tainted (no, very dishonest?) FBI ‘agent’s role in Clinton probe under review.’ Led Clinton Email probe. @foxandfriends Clinton money going to wife of another FBI agent in charge.”