
An ex-FBI informant accused of lying about President Joe Biden and his son Hunter has high-level ties with Russian intelligence, US prosecutors say.
The allegations against Alexander Smirnov, 43, were outlined in new Department of Justice filings in the case on Tuesday.
Mr Smirnov is accused of lying when he claimed bribes were paid to the Bidens via a Ukrainian energy firm, Burisma.
He was charged last week with giving false statements to the FBI.
Mr Smirnov's claims were part of an ongoing effort by Republicans to impeach President Biden.
He was arrested in Las Vegas, Nevada, on Thursday after returning from an overseas flight, the justice department said.
Prosecutors had asked for Mr Smirnov, a dual US-Israeli citizen, to be held without bail, arguing that he has no ties to Las Vegas, but does have contacts with Russian intelligence agencies.