The judge overseeing former President Donald Trump's classified documents case is raising questions about special counsel Jack Smith's use of an out-of-district grand jury to conduct his probe.

U.S. District Judge Aileen Cannon is demanding answers from Smith on his office's use of another grand jury to purportedly continue to investigate Trump's alleged mishandling of classified documents after leaving office, even though Trump has already been indicted on charges by a separate grand jury impaneled in Florida.

The development came in a stinging ruling Judge Cannon issued Monday morning, in which she ordered two sealed filings submitted by Smith on her docket struck from the record.

The filings were tied to the motion from Smith's team last week seeking a hearing on potential conflicts of interest that could arise due to the lawyer for Trump aide and co-defendant Walt Nauta -- who was charged in the indictment along with Trump -- also representing other witnesses who could be called against Nauta in the case.

"The Special Counsel states in conclusory terms that the supplement should be sealed from public view 'to comport with grand jury secrecy,' but the motion for leave and the supplement plainly fail to satisfy the burden of establishing a sufficient legal or factual basis to warrant sealing the motion and supplement," Cannon said in the ruling.

Cannon, in the ruling, then asked for Nauta's attorney, Stanley Woodward, to file a motion stating his concerns about "the legal propriety of using an out-of-district grand jury proceeding to continue to investigate and/or to seek post-indictment hearings on matters pertinent to the instant indicted matter in this district."

Cannon said that motion, as well as any related motions from Trump's attorneys, is due by Aug. 17.

Cannon's order didn't directly explain why she is seeking arguments at this juncture regarding the legality of using an out-of-district grand jury.

The judge then ordered the special counsel to reply on or before Aug. 22.

Although Cannon doesn't specify the location of the other grand jury, ABC News has previously reported that sealed proceedings in the classified documents probe were heard by a grand jury in Washington, D.C.

Trump pleaded not guilty in June to 37 criminal counts related to his handling of classified materials, after prosecutors said he repeatedly refused to return hundreds of documents containing classified information ranging from U.S. nuclear secrets to the nation's defense capabilities, and took steps to thwart the government's efforts to get the documents back.

Nauta, his longtime aide, also pleaded not guilty to related charges.

A superseding indictment subsequently charged Trump, Nauta, and Carlos De Oliveira, the head of maintenance at Trump's Mar-a-Lago estate, with two obstruction counts based on allegations that the defendants attempted to delete surveillance video footage at Mar-a-Lago in the summer of 2022.

Trump has denied all charges and denounced the probe as a political witch hunt.