A California man who prosecutors have accused of lying to federal agents and making false criminal allegations against President Biden and his son Hunter is now being charged again with tax evasion by special counsel David Weiss, according to court records.

Alexander Smirnov was an FBI informant for about a decade, providing federal investigators with information about what his defense attorneys claimed in court filings demonstrated an “undivided, years-long loyalty to the United States.”

But Weiss — the Trump-appointed Delaware U.S. attorney who stayed on during the Biden administration and was later appointed by Attorney General Merrick Garland as special counsel to pursue the Hunter Biden investigation — alleged in a February 2024 indictment that Smirnov made unlawful false statements to FBI employees about Hunter and Mr. Biden dating back to 2020.

Smirnov was accused of lying to investigators when he told them the two Bidens had each accepted $5 million from Ukrainian energy company Burisma. According to charging documents filed against him, the allegations were “false as the defendant knew.”

Smirnov, who according to court documents was born in Ukraine, pleaded not guilty to the charges and in court documents his defense team accused prosecutors of charging their client “based on Hunter Biden’s rejection of plea agreements.” He remains in custody pending trial.

On Nov. 21, just weeks before he was scheduled to go on trial on Dec. 3, federal prosecutors in Weiss’ office filed a little-noticed indictment in a separate case against Smirnov, alleging that he illegally stole millions of dollars concealed income from the IRS between 2020 and 2022.

According to court documents, Smirnov spent unreported income on a Las Vegas apartment, a Bentley and payments on credit card debt. Prosecutors did not name the alleged source of the funds, but the dates and amounts of payments to him from a single company identified in their filing as “Company 1” match payments Smirnov allegedly made from the Economic Transformation Technologies Corporation received in the court documents in Smirnov’s other case. The new charges do not indicate any wrongdoing by Economic Transformation Technologies Corporation. Additional income came from an unnamed person, the new indictment states.

“In order to conceal the millions of dollars in income he received in 2020, 2021 and 2022, defendant prepared and filed false Forms 1040, U.S. federal income tax returns, for himself and on behalf of the domestic partner, containing false and “contained fictitious income and expenses,” according to the 27-page indictment filed last week.

According to newly released court records, the judge who presided over Weiss’ first case against Smirnov – District Judge Otis Wright – held a status conference on Tuesday and postponed his upcoming trial on the false statement charges until January.

In response to the new tax charges, David Chesnoff, Smirnov’s attorney, told CBS News, “Mr. Smirnov intends to defend this case as vigorously as he vigorously defended the first case.”

A spokesman for Weiss declined to comment when contacted by CBS News.

Prosecutors claimed earlier this year that Smirnov’s false claims against the Bidens were captured in an FBI document known as FD 1023. Republicans in Congress previously pointed to the bribery allegations in the document as evidence of wrongdoing and fought with the FBI over the release of the document. Investigators now believe they were false allegations.

Smirnov’s lawyers have argued in court filings that the case “smacks of political bias.” But prosecutors pushed back, writing this month that Smirnov “has never presented any findings to the government or presented evidence to this court to support his unfounded claims – in fact, there is no such evidence because the claims are unfounded.”

In court papers filed earlier this year, the special counsel said Smirnov had told the FBI about contacts with foreign intelligence officials, “including Russian intelligence services, and had had such contacts recently.” Defense attorneys in their own court filings called the allegations of Russian ties baseless.

Aside from the specific charges at issue, law enforcement experts told CBS News earlier this year that growing questions about Smirnov’s truthfulness should prompt a review of all cases in which he was involved. A CBS News investigation The study, published earlier this year, found that serious doubts about Smirnov’s credibility were raised almost a decade ago.

The FBI declined to comment on the results of the CBS News investigation earlier this year.

Weiss secured a conviction against Hunter Biden in Delaware illegal weapons charges and an admission of guilt by the president’s son in a second case in California in which Hunter Biden admitted it Tax fraud. He is scheduled to be sentenced in both cases later this month.

The trial conviction and guilty plea were the result of a protracted legal battle between Weiss’ office and Hunter Biden’s legal team after an initial plea deal and diversion agreement failed and was ultimately rejected by a federal judge in 2023.

The special counsel has been criticized by members of Congress and whistleblowers over his handling of the Hunter Biden investigation.

Daniel Klaidman, Scott MacFarlane,

Jessica Kegu and Pat Milton contributed to this report.