LOS ANGELES — US officials have charged baseball sensation Shohei Ohtani's long-time interpreter, Ippei Mizuhara, with stealing millions from the sports star.

The lead prosecutor in California accused Mizhuara of impersonating Ohtani to banks and to place wagers.

"Ohtani is considered a victim in this case," US Attorney Martin Estrada told reporters at a news conference in Los Angeles on Thursday.

Mizuhara, 39, was fired last month as news of the alleged theft emerged.

Prosecutors claim that the interpreter used Ohtani's money to place bets and deposited his winnings into an account that he controlled.

Between November 2021 and January 2024, officials said he wired more than $16m (£13m) in unauthorized transfers from Ohtani's account.

"Mizuhara did all this to feed his insatiable appetite for illegal sports gambling," Estrada said.

The charging document alleges that Mizuhara, who acted as Ohtani's de facto manager, took advantage of the fact that the Japanese sports star does not speak English.

It said he called bank officials and "falsely identified himself as [Mr] Ohtani to trick employees into authorizing wire transfers from [Mr] Ohtani's bank account to associates of the illegal gambling operation".

From January to March 2024, Mizuhara also allegedly purchased $325,000 in baseball cards using money taken from Ohtani's account.

An LA-based defence lawyer representing Mizuhara declined to comment on the charges on Thursday.

Last week, Ohtani sat for an interview with prosecutors and denied that he allowed the interpreter access to his finances.

"[Mr] Ohtani provided his cellphone to law enforcement, who determined that there was no evidence to suggest that [Mr] Ohtani was aware of, or involved in, [Mr] Mizuhara's illegal gambling activity or payment of those debts," according to the prosecutor's statement.

The criminal charge of bank fraud carries a sentence of 30 years in federal prison. The New York Times reports he is negotiating a plea deal with prosecutors.

Sports betting is legal in 38 states in America but it remains illegal in California.

Major League Baseball has its own policy that bans "any player, umpire, or Club or League official or employee" from betting on baseball games and placing bets with illegal bookmakers.

Estrada on Thursday told reporters that there is no evidence to suggest that Mizuhara placed any bets on baseball games.

Ohtani signed a record 10-year, $700m contract with the Dodgers before this season, becoming the face of the sports franchise. He had just won his second unanimous American League MVP award.

His stint in the US started in 2018, and Mizuhara had been a constant companion. He and his wife were recently seen in a picture that revealed Ohtani's wife, Mamiko Tanaka, after weeks of speculation.

Last month, Ohtani told reporters at an LA Dodgers news conference: "I'm very saddened and shocked that someone who I trusted has done this.

"Ippei has been stealing money from my account and has told lies," he said, speaking with the help of a different interpreter. — BBC