Former Trump campaign aide Sam Nunberg arrived at a federal court in Washington, D.C., on Friday to testify before a grand jury after threatening to ignore a subpoena from special counsel Robert MuellerRobert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE.

Nunberg arrived at the courthouse early Friday morning and used the public main entrance to enter the building, according to reports. Politico reports other witnesses, as well as Mueller’s investigators, have typically used nonpublic entrances to enter the courthouse.

When asked by reporters if he would speak following his testimony, Nunberg said “no,” according to Politico.

ADVERTISEMENT

Nunberg’s testimony comes after a bizarre series of television interviews on Monday in which he revealed he had been subpoenaed by Mueller’s investigators, who demanded he turn over correspondences with Trump and several other top campaign and White House officials.

"When I got the subpoena it was ridiculous to me. Why should I hand them over every email I’ve had with Steve BannonStephen (Steve) Kevin BannonRatcliffe, Schiff battle over Biden emails, politicized intelligence Juan Williams: Trump's search for dirt falls flat Sunday shows preview: Coronavirus cases surge in the Midwest; Trump hits campaign trail after COVID-19 MORE or Roger StoneRoger Jason StoneTrump grants clemency to five nonviolent offenders Trump remarks put pressure on Barr DOJ veteran says he's quitting over Barr's 'slavish obedience' to Trump MORE since November, since November of 2015?" Nunberg said during an interview on MSNBC.

The former Trump campaign aide also told The Washington Post that he was summoned to appear before the grand jury but planned to refuse.

“Let him arrest me,” Nunberg told the Post. “Mr. Mueller should understand I am not going in on Friday.”

During the interviews, he also predicted Mueller has evidence of criminal wrongdoing committed by Trump.

“I think he may have done something during the election,” Nunberg told NBC.

The White House denied those claims, calling them incorrect.

Nunberg abruptly reversed course in a Tuesday interview with The Associated Press, saying he would cooperate with Mueller after all.

"I’m going to end up cooperating with them," he said.

It was also reported on Tuesday that Nunberg told Fox Business Network's Charlie Gasparino that he intends to get treatment following the grand jury appearance.

When asked what specifically Nunberg would be treated for, Gasparino referred to a Monday report he provided on Fox Business.

"When I interviewed [Nunberg], and I interviewed him early, he admitted to me he was drinking," Gasparino reported.

"He’s also going to seek treatment for what ails him," he continued. "There’s something. Drinking I believe is a big part of it, and that’s what happened yesterday."

Nunberg worked as an aide early in Trump's presidential campaign until he was fired for allegedly breaching a confidentiality agreement and for revelations of racially charged social media posts he wrote in August 2015.