US President Joe Biden's son, Hunter, has pleaded not guilty to tax offences in a California federal court.

He was indicted last month on nine criminal counts, including for failing to pay his taxes on time from 2016 to 2019, filing false tax returns in 2018 and tax evasion.

If convicted on these charges, Mr Biden could face up to 17 years in prison.

He is also facing federal charges over felony gun offences, to which he has already pleaded not guilty.

Mr Biden, 53, made his first appearance in the tax case at a downtown Los Angeles courtroom on Thursday afternoon, where a sea of cameras had gathered outside and US Secret Service officers had earlier conducted a security sweep.

The 30-minute arraignment was the latest development in a five-year investigation by federal prosecutors into Mr Biden's finances.

Over the summer, he appeared to be close to a plea deal that would see him admit wrongdoing on his tax offences, undergo drug treatment and monitoring for two years to resolve his gun offences, and avoid jail time.

But the agreement, which was heavily criticised by Republicans as a "sweetheart deal", collapsed under scrutiny from a judge.

As a result, Mr Biden was indicted in Delaware in September on three charges related to his illegal purchase of a firearm in 2018.

According to the 56-page charge sheet filed against Mr Biden in December over his tax charges, he made more than $7m (£5.5m) in gross income between 2016 and 2020 from business dealings in Ukraine, and related to connections from Romania and China.

Prosecutors say Mr Biden "wilfully" failed to either pay or file his taxes to the Internal Revenue Service from 2016 to 2019, instead spending his money on personal extravagances.

"Between 2016 and Oct 15, 2020, the defendant spent this money on drugs, escorts and girlfriends, luxury hotels and rental properties, exotic cars, clothing, and other items of a personal nature, in short, everything but his taxes," the document states.

Both the tax and gun charges span a period when Mr Biden was addicted to alcohol and crack cocaine.

In his memoir Beautiful Things, he wrote that he had abused substances to cope with the grief of losing his older brother Beau to brain cancer in 2015.

Since then, Mr Biden says he has become sober.

He has also paid off all his tax debts, including penalties and interest, largely with the help of loans from Kevin Morris, a close friend and LA-based entertainment attorney.

But Mr Biden's latest indictment presents a fresh challenge to his father, who is seeking re-election to the White House later this year.