Updated September 7, 2023 at 1:24 PM ET

Federal prosecutors say they will seek an indictment against Hunter Biden, President Biden's son, relating to gun charges by the end of the month, according to new court documents filed Wednesday.

The new development comes a month after U.S. Attorney General Merrick Garland appointed David Weiss as special counsel in the investigation into the president's son, following a plea deal struck between Hunter Biden and federal prosecutors that fell apart.

"The Speedy Trial Act requires that the Government obtain the return of an indictment by a grand jury by Friday, September 29, 2023, at the earliest. The Government intends to seek the return of an indictment in this case before that date," the filing states.

Specifics about the charges that Weiss will seek were not disclosed directly in the latest filing.

In June, Weiss' office said Biden possessed a firearm in October 2018 despite knowing he was an unlawful user of and addicted to a controlled substance.

Abbe Lowell, one of Biden's attorneys, told NPR in a statement they believe the signed and filed diversion agreement "remains valid" and prevents any additional charges from being filed against him.

"We expect a fair resolution of the sprawling, 5-year investigation into Mr. Biden that was based on the evidence and the law, not outside political pressure, and we'll do what is necessary on behalf of Mr. Biden to achieve that," Lowell said in the statement.

In a court filing of their own Wednesday, Biden's attorneys said he has continued to comply with the restrictions of the firearm diversion agreement — which required him to remain drug-free without committing additional crimes in order for his gun charge to be dismissed.

"Mr. Biden has been following and will continue to follow the conditions of that Agreement, which the U.S. Attorney's Office agreed and signed and informed the Court on July 20, 2023 that the Probation Office had agreed to and had recommended be put into effect," the filing said.

Back in June, Biden agreed to plead guilty to two misdemeanor offenses related to his taxes and business dealings. Federal authorities also charged Biden with a felony firearm offense, in which he agreed to enter a pretrial diversion agreement that would allow him to avoid prosecution.

According to Weiss, Biden did not pay federal income taxes for either 2017 or 2018 despite owing more than $100,000 in taxes each year.

NPR's Carrie Johnson contributed to this report. contributed to this story

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