The Los Angeles Dodgers on Tuesday fired Mizuhara over allegations of illegal gambling and theft.
Multiple US media reported that Mizuhara had a large amount of debt due to illegal gambling on sports and used Ohtani's money to pay off debts of 4.5 million dollars.
The Associated Press reported that a spokesperson for the US Internal Revenue Service, or IRS, said on Thursday that the IRS has launched an investigation into Mizuhara and Mathew Bowyer, an alleged bookmaker, on suspicion of illegal gambling.
A lawyer for Bowyer told the AP that Bowyer had never made direct contact with Ohtani, adding that Bowyer's house had been searched.
Who is Mizuhara Ippei, Ohtani's interpreter?
Mizuhara Ippei, 39, was born in Hokkaido. He moved to Los Angeles when he was a child and graduated from a university in the United States.
Mizuhara had served as an interpreter for foreign players in the Hokkaido Nippon-Ham Fighters in Japanese professional baseball from 2012, when Ohtani joined the team during the off-season.
After Ohtani signed a contract with the Los Angeles Angels in 2017, the team hired Mizuhara as Ohtani's personal interpreter. He followed Ohtani when he joined the Los Angeles Dodgers last year.
Mizuhara has been spotted with Ohtani serving as his interpreter, as a driver and as a practice partner at the stadium.
In November 2021, when Ohtani became the season's Most Valuable Player, Ohtani said Mizuhara supported him during difficult times.
Illegal gambling
Sports gambling is allowed in about 40 US states, but it is illegal in California, where Mizuhara and Ohtani are both residents.
In Major League Baseball, players and staff members are totally banned from gambling on baseball. But they are allowed to gamble on other sports as long as they are legal.
These rules are shared with players at training every spring. In fact, they were explained at the Dodgers camp last month.
Mizuhara told US sports network ESPN that his bets were placed on international soccer matches, the NBA, the NFL, and college football. He said he never bet on baseball and had no idea that the bookmaker was illegal.
ESPN reported that during a 90-minute interview Tuesday night, Mizuhara said Ohtani agreed to pay the money to cover Mizuhara's gambling debts. But the next day he said Ohtani did not know anything about the gambling.
Lawyers for Ohtani told NHK by e-mail: "Shohei has been the victim of a massive theft, and we are turning the matter over to the authorities."
A spokesperson for the Dodgers reportedly said Mizuhara told the team on Wednesday night that he has an addiction and the entire situation was his fault.
Gambling addiction
Gambling addiction is a recognized mental health diagnosis that affect the lives of people who want to stop gambling on things such as horse racing, bicycle racing and pachinko, but can't.
Japan's health ministry says a gambling addiction is characterized by accumulating debt, taking days off from work and school, neglecting sleep and meals, and worsening relationships with other people.
The Japanese government has drawn up a plan and started taking measures against gambling addiction. While many people can enjoy gambling in a healthy manner, the government estimates 2. 2 percent of adults in Japan are suspected of being addicted to gambling.