Jurors in the Hunter Biden gun case have begun deliberating, and must now decide the fate of the US president's son.

The 54-year-old is accused of lying about his drug use on a federal form while buying a weapon in 2018, and of illegally possessing a firearm while he was allegedly a drug user.

For days, prosecutors presented evidence to suggest that Mr Biden was in the throes of addiction when he purchased the gun in Delaware.

His defence team say he was in recovery and therefore not a drug user at the time.

Mr Biden, who did not testify, denies the three related charges. If convicted, he could face up to 25 years in prison.

The BBC briefly questioned Mr Biden in downtown Wilmington after the jury began deliberations on Monday.

"I think [today] went well," Mr Biden said. "We'll see though. We have to wait for the jury to come back."

In a lengthy closing argument, prosecutor Leo Wise said "no-one is above the law" and the case is "no more important, or less important, because of who the defendant is".

"The central issue in this case is whether he was an addict, and knew that he was," Mr Wise added.

To make the government's case, Mr Wise pored over witness testimony from Mr Biden's former partners and his own memoir to try to show he was an active drug user around the time he bought the gun.

The evidence, Mr Wise said, was "personal. It was ugly, and it was overwhelming".

Mr Biden's defence team argue he was in recovery at the time, so was truthful when he indicated on the paperwork that he was not a drug user.

His lawyer, Abbe Lowell, repeatedly pointed out to jurors that none of the text messages or witness testimony presented in court referenced "actual drug use" at the time of the purchase, arguing that the prosecution's case rests on "suspicion" and "conjecture".

Mr Lowell accused prosecutors of using evidence of drug use over many years.

As an example, Mr Lowell pointed out that testimony from Mr Biden's ex-girlfriend, Zoe Kestan, revealed “no pipes, no scales, no drugs, not even alcohol" at the time in question.

Mr Biden's family members sat in the row behind him in Delaware's federal court, including First Lady Jill Biden - his step-mother and the president's wife - Ashley Biden, his half-sister, as well as the James and Valerie Biden, the president's siblings.

Several visibly bristled when the prosecution said Mr Biden had "four years of active addiction", shaking their heads.

Mr Biden, for his part, spent long periods staring intently at jurors as the closing arguments went on, occasionally taking notes and conferring with his legal team.

During a break, his wife Melissa Cohen Biden embraced him and patted him on the shoulders, whispering into his ear.

The start of proceedings on Monday focused on a legal technicality. Mr Biden's lawyers wanted the 12 jurors to be told during jury instructions that he had filled out the form "in good faith". The prosecution disagreed.

The discrepancy is linked to the question of whether Mr Biden "knowingly" lied on the form.

Last week, prosecutors played excerpts from an audiobook of Mr Biden's memoir, in which he talks about being addicted to crack cocaine for four years, a period that overlapped with his gun purchase.

The court also heard from Mr Biden's ex-romantic partners, including Hallie Biden. Hallie - Mr Biden's brother's widow - testified that she found "remnants" of crack cocaine in Mr Biden's car, along with the gun.

However, during cross-examination, Ms Biden confirmed she had not seen him using drugs around the time of his gun purchase.

Throughout the trial, the defence has attempted to cast doubt on the memories of the prosecution’s witnesses.