An ex-FBI informant has been charged with making false statements about an alleged bribery scheme involving a Ukrainian company, President Joe Biden and his son Hunter.

Alexander Smirnov, 43, is accused of lying about the Bidens accepting payments from energy firm Burisma.

The Justice Department said Mr Smirnov gave false statements to the FBI because he disliked President Biden.

Republicans had relied on his claims in an ongoing bid to impeach Mr Biden.

Hunter Biden, who has resolutely denied the allegations against him, is due to testify before the House Oversight Committee later this month about the accusations.

Mr Smirnov was arrested in Las Vegas on Thursday after returning from an overseas flight, the Justice Department said. He was charged with making a false statement and creating a false and fictitious record.

In a 37-page indictment document released on Thursday, Special Counsel David Weiss - who has overseen the investigation of Hunter Biden - accused Mr Smirnov of providing "false derogatory information" to the FBI about the president and his son in June 2020.

This information was provided after Mr Biden was cemented as the Democratic presidential candidate ahead of the 2020 election, prosecutors said, and after Mr Smirnov had expressed bias against the former vice-president.

Congressional Republicans have used Mr Smirnov's allegations over the last year in their impeachment inquiry into President Biden.

When announcing the inquiry, then-House Speaker Kevin McCarthy said "a trusted FBI informant has alleged a bribe to the Biden family".

Republicans later successfully pushed the FBI to release their memos on Mr Smirnov's claims.

At the time, senior congressional Republicans acknowledged the allegation was unverified, and there was no evidence that Joe Biden had received any payments from Ukraine.

Mr Smirnov had originally alleged that Burisma officials said they hired the president's son Hunter to "protect us, through his dad, from all kinds of problems" during a series of meetings in 2015 and 2016.

At the time, Mr Biden was serving as vice-president under Barack Obama, and his son Hunter was a board member of Burisma.

Burisma was also the subject of a criminal investigation conducted by the then-Ukrainian prosecutor general.

Mr Smirnov claimed that the company had paid $5m each to Mr Biden and his son, so that Hunter "will take care of all of those issues through his dad", referring to the company's legal troubles.

Prosecutors said that, in reality, Mr Smirnov had only spoken with Burisma officials in 2017, after Mr Biden was no longer vice-president, and after the then-Ukrainian Prosecutor General had been fired in February 2016.

"In other words, when [Joe Biden] had no ability to influence US policy and when the Prosecutor General was no longer in office," the indictment stated.

Prosecutors added that Mr Smirnov "transformed his routine and unextraordinary business contact with Burisma in 2017 and later into bribery allegations against [Joe Biden]", after expressing bias against the president and his candidacy.

When questioned again by FBI agents in 2023, Mr Smirnov allegedly changed elements of his story and made new allegations after claiming to have met with Russian officials.

If convicted, Mr Smirnov faces a maximum of 25 years in prison.