An attorney who is representing 17 accused Jan. 6 Capitol breach defendants has disappeared, possibly suffering from COVID-19, according to a court filing on Monday.

Acting U.S. Attorney Channing D. Phillips said in a court document (pdf) that nearly 20 cases related to the Jan. 6 incident are not proceeding after John Pierce, the lawyer, went missing.

Pierce, according to the court filing, is “reportedly ill with COVID-19, on a ventilator, and unresponsive.” Pierce’s law firm associate, Ryan Marshall—who is not a licensed attorney—has been appearing in Pierce’s place at court hearings and proceedings. Marshall also was the one who revealed Pierce’s alleged hospitalization and condition, said the filing.

The lawyer, who generally posts on Twitter several times per day, has not posted since Aug. 20.

“Because Mr. Pierce is unavailable and Mr. Marshall cannot ethically or legally represent Mr. Pierce’s clients,” Phillips said, “the government is making the Court aware of Mr. Pierce’s reported illness so that it can take any steps it believes necessary to ensure the defendant’s rights are adequately protected while Mr. Pierce remains hospitalized.”

But later in the court filing, the U.S. attorney’s office said it obtained “conflicting information about Mr. Pierce’s health and whereabouts.”

When it was revealed publicly that Pierce was hospitalized with COVID-19, a report from NPR, citing unnamed sources, said that he may have been suffering from dehydration, exhaustion, and is believed to have symptoms related to COVID-19.

And a colleague of Pierce, Brody Womack, told Business Insider that Pierce “appears to have been suffering from dehydration and exhaustion in relation to his tireless work on behalf of his clients, including the many defendants he represents in connection with the January 6, 2021 protest at the Capitol.”

On Aug. 26, Marshall appeared in place of Pierce, telling a U.S. attorney’s assistant that he hasn’t had any contact with Pierce and adding that one of his friends “had told him that Mr. Pierce was sick with COVID-19 and another had said he was not,” the filing said.

“From the government’s perspective,” said Phillips’ office, “given Mr. Pierce’s reported illness and the fact that Mr. Marshall is not a licensed attorney, this case is effectively at a standstill.”

Even though Marshall “has been the government’s main or sole point of contact for many of the defendants represented by Mr. Pierce, the government does not believe it appropriate to continue to communicate with him in Mr. Pierce’s absence, during which he would necessarily be acting without supervision by a licensed attorney,” the court document said.

Some of Pierce’s clients said they are starting to become concerned.

Paul Rae, an alleged Proud Boy from Florida who has pleaded not guilty, told ABC News on Monday that he is “a bit concerned” about the lawyer’s health and the overall situation regarding his representation. An associate of Pierce, Rae said, told him that the attorney isn’t on a ventilator and is recovering.

“Unless I’m being lied to, I’m hearing ‘Don’t be concerned,’” Rae told the network. “I don’t know what’s going on.”

The Epoch Times contacted Pierce’s office for comment. When reached for comment via telephone, the phone lines for his law firm appeared to be disconnected.