WASHINGTON (AP) — Federal prosecutors plan to ask a grand jury to indict President Joe Biden’s son Hunter by the end of the month, according to court documents filed Wednesday.

The exact charges the president’s son would face were not immediately clear, but appeared related to a gun possession charge in which he was accused of having a firearm while being a drug user. He has also been under investigation by federal prosecutors for his business dealings.

U.S. Attorney for Delaware David Weiss, newly named a special counsel in the case, referred to a seeking an indictment before Sept. 29 in a status report required by Judge Maryellen Noreika.

Defense attorneys have argued that an agreement sparing Hunter Biden from prosecution on a felony gun charge remains in place. It was part of a plea deal on misdemeanor tax offenses that fell apart during a court appearance in July.

Biden was charged in June with two misdemeanor crimes of failure to pay more than $100,000 in taxes from over $1.5 million in income in both 2017 and 2018. He had been expected to plead guilty in July, after he made an agreement with prosecutors, who were planning to recommend two years of probation. The case fell apart during the hearing after Noreika, who was appointed by President Donald Trump, raised multiple concerns about the specifics of the deal and her role in the proceedings.

Attorneys for Biden did not immediately return messages seeking comment Wednesday.