Hunter Biden was charged with two counts of making false statements when claiming on forms required for the 2018 gun purchase that he was not using drugs illegally at the time.

A third charge said that, based on the false statements, he illegally possessed the gun during an 11-day period in October that year.

If convicted on all three charges, Biden could in theory face 25 years in prison, though in practice the charges are seldom punished by any jail time.

In attesting that he was not an unlawful user of drugs at the time he bought the Colt Cobra revolver, Biden "knew that statement was false," the Justice Department said.

The indictment came two days after Republicans in Congress opened an impeachment probe against Joe Biden, alleging that when he was vice president he benefitted financially from his son's foreign business dealings.

The gun charges were filed by Justice Department Special Counsel David Weiss, who has been investigating Biden since 2018 over various allegations, mostly related to his overseas business deals.

- Plea deal collapsed -

Two months ago a plea deal between Biden and Weiss, covering the gun charge as well as alleged tax violations, went sour over differences of whether the president's son could face additional charges.

In the July deal, Biden, 53, agreed to plea guilty in federal court in Delaware to two minor tax charges.

In exchange he was offered probation, as he had already paid what he owed the government along with penalties.

In the same deal, Weiss agreed to suspend the felony gun charge if Biden completed "pretrial diversion," which often involves counseling or rehabilitation.

But in a dramatic July 26 hearing, the deal collapsed over the issue of whether Biden would have been immune from any other charges also investigated by Weiss, including possible crimes related to his business dealings in Ukraine, China and elsewhere.

The judge mentioned the possibility that Biden could be charged as having acted as a lobbyist for foreign governments without registering with the Justice Department.

Three weeks later, after the deal collapsed, Weiss dropped the tax charges and indicated in a court filing that new charges would be brought in other states.

And he told the Delaware court that an indictment on the gun charge would come by the end of September.

The legal troubles of Biden, a Yale-trained lawyer and lobbyist, pose an increasing challenge to his father's bid for a second term.

Without offering any evidence, Republicans have accused President Biden's Justice Department of protecting his son and have accused Weiss, a Republican appointee, of going easy on Hunter.

On Tuesday Republicans in the House of Representatives formally opened an impeachment inquiry against Joe Biden.

They alleged, without offering hard evidence, that while vice president in 2015-2016, Biden intervened to protect an allegedly corrupt Ukrainian energy company, Burisma, where Hunter Biden sat on the board.

Republicans allege Joe Biden and his family reaped large sums for helping Burisma.