Las Vegas, Nevada - An FBI informant charged with lying about President Joe Biden and his son has been arrested again, just days after being released on bail, his lawyers said in a court filing Thursday.

Alexander Smirnov (43), a dual US and Israeli national, was arrested last week and indicted for fabricating claims that Hunter Biden demanded multi-million-dollar bribes from Ukrainian firm Burisma – on whose board he was serving at the time – to protect it from an investigation when his father was US vice president.

Earlier this week Smirnov was released by a court in Nevada, over prosecutors' objections that he was likely to abscond, on the condition that he surrender his passports and be subject to GPS monitoring.

Then, in an unusual move, he was detained again.

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"On the morning of February 22, 2024, Mr. Smirnov was arrested for a second time... while at the undersigned counsel's law office for meetings with counsel," his lawyers David Chesnoff and Richard Schonfeld said in a court filing.

"It should further be noted that the fact that the Defendant was attending a legal consultation meeting at his attorneys' office contradicts the notion that he is a risk of flight."

The motion, filed in Clark County, Nevada, seeks an immediate hearing to order Smirnov's release from custody.

The grand jury indictment against Smirnov that was unsealed last week appears to undermine the impeachment effort against Biden being put together by congressional Republicans, who had touted Smirnov's evidence as proof the Bidens were collectively involved in a criminal enterprise.

The claim that Hunter Biden leveraged his father's name for personal gain has been central to a Republican narrative, pushed heavily by Donald Trump, that Joe Biden is corrupt.

The indictment said that for at least a decade Smirnov was acting as a "confidential human source" for the Federal Bureau of Investigation, providing his handler with information to be used in criminal investigations, and that some of what he passed on was false.

A subsequent filing claimed that Russia's intelligence services were the root of the false information Smirnov had given to his FBI handler about the Bidens. It also said that the efforts were not only historical, but continued and were an apparent effort to sway the 2024 presidential election.

"During his custodial interview on February 14, Smirnov admitted that officials associated with Russian intelligence were involved in passing a story about (Hunter Biden)," prosecutors said this week.

Smirnov faces one charge of making a false statement, and one of creating a false and fictitious record, in his dealings with an FBI investigation.

If convicted, he could be jailed up to 25 years.