EXCLUSIVE – Multiple administration officials tell Fox News that when Robert Mueller met with President Trump in May of 2017, Mueller was indeed pursuing the open post as the director of the FBI – something the former Russia probe special counsel denied under oath during congressional testimony this summer.

These officials also told Fox News government documents showed Mueller was pursuing the job as a candidate himself.

It came as emails released this month through a Freedom of Information Act request by the conservative group Judicial Watch seemed to indicate Mueller knew there was a real possibility he could be named special counsel if he wasn’t chosen as the next FBI director.

MUELLER REJOINS WILMERHALE LAW FIRM, IN LATEST POST-RUSSIA PROBE LANDING

“The boss and his staff do not know about our discussions,” then-Deputy Attorney General Rod Rosenstein said in an email to Mueller on May 12, 2017. Rosenstein’s boss was then-Attorney General Jeff Sessions, who had recused himself from the Russia probe, meaning the president would not have known either.

A source close to Rosenstein confirmed to Fox News that he had confidential conversations with Mueller about whether he would be willing to serve in the event he needed to appoint a special counsel. These conversations began on May 12, 2017, prior to Mueller's meeting with the president on May 16, 2017, the source acknowledged.

At the time of the now-famous May 16, 2017 meeting, James Comey had been fired as FBI director just days before and -- unbeknownst to the president -- Mueller would end up being named special counsel the very next day to oversee the Trump-Russia probe.

The president has repeatedly claimed that Mueller – who served as FBI director under Presidents George W. Bush and Barack Obama – met with him about returning to lead the Justice Department. The president has pointed to this to argue it was a conflict for Mueller to become special counsel, saying he opted against hiring Mueller as FBI director.

But Mueller, in his July congressional testimony, denied the claim, saying he believed he was giving “input” to the president about the position.

“My understanding was I was not applying for the job,” Mueller said on July 24. “I was asked to give my input on what it would take to do the job.”

John Dowd, who served as the president’s attorney during the probe, ripped Mueller for meeting with Trump, calling it the “most dishonorable conduct I have ever witnessed.” He added, “Capt. Robert Mueller, USMC, sits in front of his commander-in-chief being interviewed for FBI director knowing he is going to investigate the president and never says a word.”

The president himself has claimed there were “numerous witnesses” to the meeting.

"It has been reported that Robert Mueller is saying that he did not apply and interview for the job of FBI Director (and get turned down) the day before he was wrongfully appointed Special Counsel" Trump tweeted the day of Mueller’s Capitol Hill testimony. "Hope he doesn't say that under oath in that we have numerous witnesses to the interview, including the Vice President of the United States!"

Mueller did not immediately return a request for comment from Fox News on Tuesday.

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It was announced earlier this month that Mueller rejoined the WilmerHale law firm, after concluding his work as special counsel.

In April, Mueller’s team released a report about their findings, indicating they did not find evidence of coordination between the 2016 Trump campaign and Russia while declining to reach a conclusion on whether the president's conduct during the probe amounted to obstruction.

Fox News’ John Roberts and Alex Pappas contributed to this report.