Los Angeles Dodgers superstar Shohei Ohtani said Monday he had never bet on baseball or other sports, declaring himself "saddened and shocked" at allegations his interpreter stole millions of dollars from him to pay off gambling debts.

In his first public comments on the scandal which erupted last week and led to the firing of his long-time friend and translator Ippei Mizuhara, Ohtani emphasised he had been the victim of a multi-million-dollar theft.

"I never bet on baseball or any other sports and I never have asked somebody to do that on my behalf and I have never went through a bookmaker to bet on sports," Japanese ace Ohtani said through a translator.

Ohtani, the biggest star in baseball who joined the Dodgers last December in a record-breaking US$700 million deal, said he had only learned of the revelations involving Mizuhara after last Wednesday's season-opening win against the San Diego Padres in Seoul.

Ohtani said an interview Mizuhara gave to ESPN last week, in which his translator said the star had knowingly wired money to a California bookmaker to pay off the interpreter's gambling debts was "a complete lie."

"Obviously I never agreed to pay off this debt or make payments to the bookmakers," the 29-year-old told reporters at Dodger Stadium.

"All of this has been a complete lie...Until a couple of days ago I didn't know this was happening...Ippei has stolen money from my account and told lies.

"I'm very saddened and shocked that someone who I trusted has done this," Ohtani said of the allegations.

Ohtani did not take questions from reporters and did not immediately explain how Mizuhara had been able to access his bank account to steal an amount reported to be US$4.5 million. (AFP)