Key witnesses in the probe into whether former President Donald Trump and his allies interfered with the 2020 presidential election were spotted at the Fulton County courthouse Monday as prosecutors appear poised to seek indictments.

Former state Sen. Jen Jordan and state Rep. Bee Nguyen — two Democrats who attended hearings where then-Trump lawyer Rudy Giuliani urged officials not to certify the Georgia election results — were seen by NBC News inside the courthouse.

Jordan wouldn’t confirm that she was there to testify but was overheard asking security for directions to the Fulton County District Attorney’s Office inside the building. Nguyen confirmed to reporters that she had testified before the grand jury as she exited the courthouse in the early afternoon.

Jordan and Nguyen were among several who had received subpoenas for their testimony before a grand jury this month. Another is Geoff Duncan, a Republican who was the state’s lieutenant governor during the 2020 presidential election period and was critical of Trump’s efforts to reverse his loss in the state.

Trump said in a post on his social media website Truth Social that Duncan should not comply.

“I am reading reports that failed former Lt. Governor of Georgia, Jeff Duncan, will be testifying before the Fulton County Grand Jury. He shouldn’t,” Trump wrote in a post on his social media platform, Truth Social, calling him a “loser” and a “nasty disaster.” The post also mocked CNN, where Duncan works as a contributor.

The post appeared to have the potential to open Trump up to more legal trouble — specifically a Georgia law about influencing witnesses.

The District Attorney’s Office declined comment on the post, and a representative for Trump did not immediately respond to a request for comment. Duncan also declined to comment on Trump’s post “other than he misspelled ‘Geoff.’”

The former president also continued his attacks on Fulton County District Attorney Fani Willis, who he called “phoney” and claimed was conducting a political witch hunt. “She only wants to ‘get Trump,'” he wrote in one of his all-capitalized posts.

Willis has been conducting a wide-ranging investigation since early 2021 into whether there were any “coordinated attempts to unlawfully alter the outcome of the 2020 elections” by Trump and his allies.

She enlisted a special grand jury last year that was empowered to subpoena witnesses to assist in the probe. It heard testimony from 75 witnesses, court records show. The panel recommended indicting more than a dozen people, its foreperson said on NBC’s “Nightly News” in February.

Willis’s investigation has looked at Trump’s efforts to pressure Republican Gov. Brian Kemp, GOP Secretary of State Brad Raffensperger and others about challenging the certified election results, as well as at a scheme to have a slate of alternate presidential electors in place.

Those instances also figured prominently in special counsel Jack Smith’s federal indictment earlier this month alleging Trump used “unlawful means” to try to stay in office.

Trump has pleaded not guilty in the federal case and maintains he didn’t do anything wrong in Georgia.

Security in and around the courthouse was increased last week and remained heightened Monday. Willis sent the chief judge and law enforcement officials letters earlier this year indicating her office could seek indictments in the first half of August.

“I respectfully request that judges not schedule trials and in person hearings during the weeks beginning Monday, August 7 and Monday, August 14,” Willis wrote in her letter to the chief judge in May.