SANTA ANA, Calif. -- A Southern California bookmaker who took thousands of sports bets from the former interpreter for baseball star Shohei Ohtani pleaded guilty Friday to running an illegal gambling business.

Mathew Bowyer, 49, entered the plea in federal court. He also pleaded guilty to money laundering and subscribing to a false tax return. He's due to be sentenced Feb. 7.

"I was running an illegal gambling operation, laundering money through other people's bank accounts," Bowyer told the judge.

Federal prosecutors declined to comment after the hearing.

According to prosecutors, Bowyer ran an illegal gambling business for at least five years in Southern California and Las Vegas, and he took wagers from more than 700 bettors, including Ohtani's former interpreter, Ippei Mizuhara.

Operating an unlicensed betting business is a federal crime. Meanwhile, sports gambling is illegal in California, even as 38 states and the District of Columbia allow some form of it.

Mizuhara pleaded guilty to bank and tax fraud for stealing nearly $17 million from a bank account belonging to Ohtani, who played for the Los Angeles Angels before signing with the Los Angeles Dodgers last offseason.

Federal investigators say Mizuhara, who is scheduled to be sentenced in October, made about 19,000 wagers between September 2021 and January 2024. While Mizuhara's winnings totaled over $142 million, which he deposited in his own bank account and not Ohtani's, his losing bets were around $183 million -- a net loss of nearly $41 million.

Investigators didn't find any evidence Mizuhara had wagered on baseball. Prosecutors said there also was no evidence that Ohtani was involved in or aware of Mizuhara's gambling, and the player, who cooperated with investigators, is considered a victim.

Diane Bass, Bowyer's attorney, said her client never had any contact with Ohtani. Based on the federal sentencing guidelines, she said she believes his expected sentencing range could be 30 to 37 months. Federal prosecutors said in court the maximum potential prison sentence for the offenses would be 18 years.

"Mr. Bowyer is very relieved to finally be able to accept responsibility for his conduct," Bass told reporters outside the courthouse after the hearing. "He is looking forward to receiving his sentence so that he can put this chapter behind him and he and his family can get on with their lives."

Federal prosecutors said Bowyer's other customers included a professional baseball player for a Southern California club and a former minor league player. Neither were identified by name in court filings.

Bowyer's guilty pleas are the latest sports betting scandal this year, including one that led Major League Baseball to ban a player for life for the first time since Pete Rose was barred in 1989. In June, the league banned San Diego Padres infielder Tucupita Marcano for life and suspended four other players for betting on baseball legally. Marcano became the first active player in a century banned for life because of gambling.

Rose, whose playing days were already over, agreed to his ban in 1989 after an investigation found that he'd placed numerous bets on the Cincinnati Reds to win from 1985 to 1987 while playing for and managing the team.

The league's gambling policy prohibits players and team employees from wagering on baseball, even legally. MLB also bans betting on other sports with illegal or offshore bookmakers. The penalty is determined at the discretion of the commissioner's office.

In Mizuhara's case, Bowyer was not named in the criminal complaint but popped up repeatedly as "Bookmaker 1." Federal prosecutors declined to identify him, but Bass confirmed on Friday that reference was to her client.

Mizuhara and Bowyer regularly corresponded, the court filing shows, and the communications varied between friendly messages -- Bowyer wished Mizuhara a "Merry Christmas" in early December 2022 -- and threatening ones when the interpreter failed to pay off his debts on time.

At one point, Bowyer couldn't reach Mizuhara and threatened to approach Ohtani, who was identified as "Victim A" in the court filing.

"Hey Ippie, it's 2 o'clock on Friday. I don't know why you're not returning my calls. I'm here in Newport Beach and I see [Victim A] walking his dog," the bookmaker wrote to Mizuhara on Nov. 17, 2023. "I'm just gonna go up and talk to him and ask how I can get in touch with you since you're not responding? Please call me back immediately."

The pair last corresponded March 20, the day the Los Angeles Times and ESPN broke the news of the investigation.

"Have you seen the reports?" Mizuhara wrote to Bowyer.

The bookmaker responded, "Yes," adding, "Obviously you didn't steal from him. I understand it's a cover job."

Mizuhara replied: "Technically I did steal from him. It's all over for me."