TOKYO (Kyodo) -- Japan's top prosecution office said Monday that the scope of recorded interrogations will be expanded in April amid growing criticism over instances of inappropriate conduct by prosecutors toward suspects during questioning.

The Supreme Public Prosecutors Office said it will fully record voluntary interrogations of certain suspects, including those expected to be indicted without arrest, and notified prosecution authorities across Japan of the decision the same day.

The initiative will "contribute to ensuring the fairness of interrogations," Hiroshi Yamamoto, deputy prosecutor general of the office, told Kyodo News.

Audio and visual recording is currently mandatory only for cases independently investigated by prosecutors or those subject to lay judge trials when the suspect has been arrested or detained.

The new policy will extend required recording to voluntary questioning, particularly in cases that may lead to indictment, involve disputes over the interrogation process or rely on testimony as key evidence, according to the office.

Concerns over prosecutors' conduct during questioning have grown following multiple misconduct cases, including one in which an Osaka prosecutor verbally abused a suspect in an embezzlement case.

The prosecutor allegedly yelled at the suspect and made abusive remarks. In 2024, the Osaka High Court ruled to examine the prosecutor's criminal liability in a trial.