Lawyers for an accused Russian money launderer in US custody are lobbying for their client to be included in any potential US-Russia prisoner swap for detained Wall Street Journal reporter Evan Gershkovich, according to new court filing.

The Russian man, Alexander Vinnik, is accused of running a multibillion-dollar cryptocurrency exchange that allegedly did business with drug dealers and identity thieves. He was extradited from France to California last year.

The effort to free Vinnik in a swap for Gershkovich, who was arrested in Russia in March on what US officials say are bogus espionage charges, shows how lawyers for detained Russians and Americans are making a full-court press to get their clients included in any potential exchange involving Gershkovich and Paul Whelan, another American detained in Russia.

Vinnik, who has pleaded not guilty to money laundering charges, should be "allowed to advocate publicly for his inclusion in a prisoner swap," Vinnik's lawyers argued in a May 19 court filing in a federal court in San Francisco. The motion asks a judge to reverse an order that forbids Vinnik from discussing his case publicly.

"Numerous" people with knowledge of the US-Russia prisoner swap negotiations have told Vinnik's lawyers that they should lobby publicly for his inclusion in a prisoner swap "in order to maximize the chances of such an exchange," Vinnik's lawyers, Jodi Linker and David Rizk, wrote in the filing.

The Wall Street Journal reported earlier on the filing from Vinnik's lawyer.

A Justice Department spokesperson did not immediately respond to a request for comment on the motion.

US officials have denounced the arrests of Gershkovich and Whelan and made feverish efforts to free them. But it's unclear who may be included in any potential swap.

Vinnik was among multiple names that US officials previously floated to the Russians during discussions about a prisoner swap for Whelan, CNN reported in December.

But while the US has multiple Russian cybercriminals in custody, the Kremlin will not entertain them as part of a deal for Americans charged with espionage, current and former US officials previously told CNN.

WNBA star Brittney Griner was freed from Russian custody in December in exchange for convicted Russian arms dealer Viktor Bout.

The Russian government has often rushed to try to gain custody of its citizens abroad who are accused of serious cybercrimes before US law enforcement can pounce. US prosecutors had for years been in an extradition fight with Russian authorities over Vinnik, who was arrested in Greece in 2017 and subsequently extradited to France.