The indictment – the first ever against a sitting president’s son – came after a plea agreement on tax and gun charges collapsed in July under scrutiny from a federal judge.
Charges announced on Thursday follow a multi-year investigation by David Weiss, who was appointed as US attorney for Delaware by Donald Trump in 2018 and has remained under the current administration in an effort to avoid the appearance of a conflict of interest.
Mr Weiss was appointed as special counsel in August.
Hunter Biden was set to plead guilty to misdemeanour tax charges and enter a diversion agreement related to a felony gun charge in July, but the agreement appeared to hit a snag during a federal court hearing, and the judge presiding over the case ultimately rejected the arrangement.
Prosecutors later announced they intended to seek a grand jury indictment by the end of September.
Congressional Republicans, meanwhile, continue to investigate the younger Biden and prepare an impeachment inquiry against the president, fuelled by GOP allegations that he was involved with and profited from his son’s business dealings. They have not provided any evidence that the president was influenced by or profited from such dealings while in office.
A Delaware grand jury’s indictment charges Hunter Biden with illegally owning a gun as a drug user, and with allegedly lying on a form when he bought the firearm. If convicted, he could face up to 25 years in prison, though it is highly unlikely he would face such a sentence.
The charges are expected to draw right-wing outrage and fuel Republican campaigns against the Biden family, as Mr Trump, the frontrunner for the 2024 Republican nomination for president, faces four criminal indictments spanning dozens of charges, including for crimes allegedly committed while in office.
A potential trial for Hunter Biden could play out in parallel to Mr Trump’s multiple criminal proceedings in four jurisdictions, including courtrooms in Georgia, New York, Washington DC and Florida.
The day before the Biden indictment was announced, his attorneys sued a former Trump-era White House official, Garrett Ziegler,accusing him of launching a “sustained, unhinged and obsessed campaign” against the Biden family, including hacking the alleged contents of a laptop that were central to political campaigns surrounding the 2020 presidential election, federal investigations and Republican-led congressional probes.
Court filings in the initial gun case outlined that Hunter Biden was using crack cocaine when he bought a Colt Cobra .38 special revolver from a federally licensed gun dealer in Delaware in October 2018. He indicated on a federal form that he was not using illegal narcotics at the time, according to prosecutors.
The firearm was later discovered in his car with drug paraphernalia before it was “subsequently discarded in a trashcan outside a supermarket”, the filing states.
Under the terms of the previous plea agreement, Mr Biden would have pleaded guilty to two misdemeanor counts of failing to pay his taxes in exchange for a probation sentence. Felony gun charges would have been dropped in two years if he honoured the terms of a diversion agreement, which attorneys for Mr Biden have said he had already signed and were in effect.
Republican lawmakers had denounced the plea agreement as a “sweetheart deal” as they railed against the appointment of Mr Weiss as special counsel – despite specifically requesting that Mr Weiss be given the role.
The White House and President Biden, who along with his son have repeatedly publicly addressed his addiction and struggle with drug abuse, have largely avoided discussing the case, though the president supported his son in a recent interview with MSNBC.
The Independent has requested comment from attorneys for Mr Biden.